Seconds from Disaster

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2- Tunnel Inferno is the 2nd episode of Seconds from Disaster and explores the causes of one of the worst tunnel fires.
Plot

On 24 March 1999, at 10:30 CET, Nicholas Borghi and John Whitby drive into the tunnel from the Italian side. Nicholas Borghi is a skier, heading from his home in Italy to ski resorts in France. John Whitby was driving his lorry (large freight trucks) to France. Then at 10:47 CET, a 40 ton refigerated lorry enters the French side of the tunnel. Its load is usual, 9 tons of margarine and 12 tons of flour, heading for a food factory in Milan. The driver was a 57-year-old Belgian driver called Gilbert Degraves, with 25 years of lorry-driving experience. Possibly, during its trip in the tunnel, a discarded cigerette landed in the paper air filter. The fire burning the filter spreads to the engine, causing that to burn. This small fire releases smoke not dense enough to trigger sensors that indicate visibility. If visibility is reduced by 30%, the alarm will sound. Cars passing by tried to get Degraves' attention by flashing headlights and honking at him. Finally, Degraves could not take the smoke any longer. He got out of his lorry to reach for the fire extinguisher, as drivers have done in previous lorry fires. When Degraves got the extinguisher, the lorry suddenly exploded at 10:53 CET. Degraves abandoned his lorry and ran towards Italy. Then, a queue quickly forms behind the lorry. They could not see the danger ahead. Nicholas Borghi say a bright glow, and by the time he got within 30 metres, he saw a massive flame and Degraves running away. He then reversed and headed for Italy. John Whitby saw thick black smoke billowing out of the fire and stopped his lorry. He could not reverse because his lorry was too long and Whitby abandoned it. The sensors do alarm the French control room, but not the Italian room because they turned off the sensors because of false alarms. At 10:54 CET, rescue teams from France  enter the tunnel. They were forced to abandon their vehicle and stay in a maintenance room because  of the smoke and other vehicles in the way. Then 3 minutes later, firefighters entered the tunnel from Chamonix. They also had to abort the mission because of smoke. By 11:00 CET, Italian rescuers drove into the Italian side. Whitby was by his lorry when they came. The rescue team could get within 10 metres from the lorry on fire because smoke was spreading quickly to France, and slowly to Italy. But popping tires forced them to turn back. The rescue team rescued Degraves, Whitby, and ten other drivers. Italian firefighters then came in, but the thick smoke forced them to stay in Refuge 24. Then, a team of Italian firefighters rescue all the firefighters and rescue teams trapped through the ventilation duct under the road. The 38 people left died of inhaling smoke and burned to death. The inferno burned for 53 hours, and it took 5 days for the tunnel to cool down to start repairs. Then, after 3 years of closure, the Mont Blanc Tunnel opened, with new safety features. Outside the toll booth, there are thermal sensors for lorries. Fire trucks are equipped with heat sensors, to allow sight in the smoke. There is a fire staion in the middle of the tunnel. Speed limits and vehicle distance were strictly enforced. Refuges are pressurised, and there is a video link to one control room for both entrances. Now, refuges are placed every 300 metres. There is an emergency exit at each refuge that leads into an escape route to France or Italy, under the road.
Why it all happenedEdit

The engine could overheat during the long climb up the Alps. The engine could have overheated and started the fire. Or, it could be a cigarette that landed in the air filters. The reason why the tunnel inferno was so hot was the margarine. Margarine has a lot of energy. When burned, the fire releases all that energy into heat. That is why it was so hot. 9 tons of margarine would equal a huge tank of petroleum (gasoline).

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3. The Bomb in Oklahoma City


is the 3rd episode of Seconds from Disaster, trying to understand how did a truck bomb destroy such a big building.

Plot

In retaliation against the U.S. government, Timothy McVeigh plants a bomb inside a Ryder truck in front of the Alfred P. Murrah Federal Building in Oklahoma City. Minutes later, it explodes, destroying the back of the building and killing 168 people (which includes some children inside Alfred P. Murrah's childcare center on the first floor).


How the back of the building collapses

 
The aftermath of the bombing, taken from a helicopter
When the truck explodes, it first destroys Column G20, the third column on the left directly next to the truck. Later, the shockwave blasts through the first-floor lobby and travels through the stairwell, destroying the 1st four floors supporting the building, eventually collapsing the office building.

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4- Fire on the Scandinavian Star


In 1990, the Scandinavian Star was sold to Vognmandsruten and put into service on DA-NO Linjen's route between Oslo, Norway, and Frederikshavn, Denmark. As the ship had been converted from a casino ship to a passenger ferry, a new crew needed to be trained and were given just ten days to learn new responsibilities. Master mariner Captain Emma Tiller, interviewed for the National Geographic Channel's documentary series Seconds from Disaster, stated that six to eight weeks would be a reasonable period to train a crew for a ship of the Star's size.

The documentary went on to explain that many of the crew could not speak English, Norwegian or Danish, thus further reducing the effectiveness of the response to the emergency. The insurance company Skuld's technical leader, Erik Stein, had inspected the ship shortly before, and had declared the fire preparedness deficient, for among other reasons because of defective fire doors.

During the night of 7 April 1990, at about 2 a.m. local time, fire broke out and was discovered by a passenger and was brought to the attention of the receptionist. The fire spread from deck 3 to 4 stopping at deck 5. As the stairwell and ceilings acted as chimneys for the fire to spread. Although the bulkheads were made of steel structure with asbestos wall boards, a melamine resin laminate was used as a decorative covering and proved extremely flammable in subsequent testing, spreading fire throughout Deck 3. The burning laminates produced toxic hydrogen cyanide and carbon monoxide gases. The fire then spread to Deck 4 and Deck 5.[citation needed]

When the captain learned of the fire, he attempted to close the bulkhead fire doors on Deck 3. The fire doors were not configured for fully automatic closing and did not respond since emergency alarms near the doors had not been manually triggered by passengers or crew. A vehicle storage area ventilated by large fans to remove exhaust fumes was also located nearby, and the fans pulled air through an improperly secured fire door and caused rapid fire progress from Deck 3 through Deck 4 and Deck 5 via stairways located on either end.

The captain later ordered his crew to turn off the ventilation system when he realized it was feeding the fire, and an unintended result was that smoke was able to enter passenger cabins via the door vents. Some tried to seek refuge from the smoke in areas such as closets and bathrooms or remain asleep in bed, but were eventually overcome by smoke. Those who tried to escape may have variously encountered thick smoke, confusing corridor layouts, and poorly trained crew members. The captain ordered the general alarms to be activated, told everyone to abandon ship, and sent out a mayday request. The captain and crew ultimately abandoned ship before all passengers were evacuated, leaving many still on board the burning ship even after it was towed to the harbor.[citation needed]

Investigators proposed several reasons for why many passengers did not safely evacuate:

   Many people probably did not hear the alarms due to distance between their cabins and the alarms, and due to ordinary mechanical noise of the ship systems.
   Some people probably could not find their way out because of thick smoke obscuring the exit routes and signage.
   Burning melamine panels in the hallways produced poisonous hydrogen cyanide and carbon monoxide, causing rapid unconsciousness and death.
   Numerous Portuguese crew members did not speak or understand Norwegian, Danish or English, were unfamiliar with the ship, and had never practiced a fire drill. Only a few crew members even thought to put on breathing masks before entering smoke filled corridors.
   On Deck 5, where most passenger deaths occurred, the hallways were arranged in a layout that contained dead-ends and did not otherwise logically lead to emergency exits.

The ship was towed to Lysekil, Sweden, where the fire department suppressed the fire in ten hours. 158 people, or approximately one-third of all passengers on board, died on the ship. Another victim died two weeks later from his injuries. 136 of those killed were Norwegian.[citation needed]

The Scandinavian Star had had other fires prior to 1990. On 15 March 1988, while sailing for SeaEscape on a Caribbean cruise, a fire started in the engine room when the ship was about 50 nautical miles (90 km) northeast of Cancún, Mexico. The ship was carrying 439 passengers and 268 crew members. The ship lost power and the emergency oxygen system malfunctioned, hampering the fire-fighting crew's efforts. The inability of the crew members to communicate effectively with each other and with passengers was a serious concern and created confusion during the fire fighting and evacuation activities.

During the investigation of the fire, investigators learned that unreported fires had also occurred in 1985, caused by a deep-fryer, and again just days before the 15 March 1988 fire, caused by a broken lubricating pipe.

Investigation
An Oslo security officer investigation initially cast suspicion on Erik Mørk Andersen, a Danish truck driver who died in the disaster and who had three previous convictions for arson. A later investigation in 2009 determined that there were several separate fires and that multiple people would have been needed to start them, especially if they were not familiar with the layout of the ship.[/url] A 2013 report prepared by a self-appointed Norwegian group called "Stiftelsen Etterforskning Av Mordbrannen Scandinavian Star" ("Foundation for Arson Investigation Scandinavian Star") denied that Anderson was responsible, claiming instead that multiple fires were deliberately set and the truck driver was killed by one of the first two fires (up to nine hours prior to the last fire being started).

The same 2013 report claimed that as many as nine experienced members of the crew, having joined the ship earlier in Tampa, were likely to be responsible for six separate fires on the Scandinavian Star as well as multiple acts of sabotage to both the ship and the fire crew's efforts to put out the fire.The report proposed the motive for the crime was insurance fraud, as the ship was insured for twice its value shortly before the fire broke out. The report claims that multiple people with insider knowledge of the ship were required for events to unfold as they did.

This controversial and unproven report led to renewed security officer interest; and in 2014 the investigation was officially reopened and charges dropped against the deceased suspect Erik Mørk Andersen.[url=https://en.wikipedia.org/wiki/MS_Scandinavian_Star#cite_note-reopen-2]
In March 2015 the Parliament of Norway decided to remove the statute of limitations for arson, such that criminal investigation and prosecution remains possible.

In February 2016, the retired Danish investigator Flemming Thue Jensen, who had led the post-fire investigation in 1990, claimed that the fire was sabotage and was set by members of the ship's crew; that fire doors had been propped open to allow the fire to spread; and that a third flare-up that occurred after the ship had been evacuated of passengers was caused by crew members soaking mattresses with diesel fuel.

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5. The Eschede derailment occurred on 3 June 1998, near the village of Eschede in the Celle district of Lower Saxony, Germany, when a high-speed train derailed and crashed into a road bridge. 101 people were killed and around 100 were injured. It remains the worst rail disaster in the history of the Federal Republic of Germany and the worst high-speed-rail disaster worldwide. The cause was a single fatigue crack in one wheel that, when it failed, caused the train to derail at a set of points and crash into the pillars of a concrete road bridge, causing it to collapse and crush two coaches. The remaining coaches and rear power car crashed into the wreckage.

Wheel fracture

Intercity-Express trainset 51 was travelling as ICE 884 "Wilhelm Conrad Röntgen" on the Munich to Hamburg route; the train was scheduled to stop at Augsburg, Nürnberg, Würzburg, Fulda, Kassel, Göttingen, and Hanover before reaching Hamburg.[1] After stopping in Hanover at 10:30, the train continued its journey northwards. About 130 kilometres (80 mi) and forty minutes away from Hamburg[1][time needed] and six kilometres (3.7 mi) south of central Eschede, near Celle, the steel tyre on a wheel on the third axle of the first car broke, peeled away from the wheel, and punctured the floor of the car, where it remained embedded.[citation needed]

What ensued was a series of events that occurred within minutes yet took investigators months to reconstruct. The tyre embedded in the rail car was seen by Jörg Dittmann, one of the passengers in Coach 1. The tyre went through an armrest in his compartment, between where his wife and son sat. Dittmann took his wife and son out of the damaged coach and went to inform a conductor in the third coach. The conductor, who noticed vibrations in the train, told Dittmann that company policy required him to investigate the circumstances before pulling the emergency brake. The conductor took one minute to go to the site in Coach 1. According to Dittmann, the train had begun to sway from side to side by then. The conductor did not show a willingness to stop the train immediately at that point and wished to investigate the incident more thoroughly. Dittmann could not find an emergency brake in the corridor and had not noticed that there was an emergency brake handle in his own compartment.[2] The crash occurred just when Dittmann was about to show the armrest puncture to the conductor.[1][time needed]
Derailment

As the train passed over the first of two points, the embedded tyre slammed against the guide rail of the points, pulling it from the railway ties. This guide rail also penetrated the floor of the car, becoming embedded in the vehicle and lifting the axle carriage off the rails. At 10:59 local time (08:59 UTC), one of the now-derailed wheels struck the points lever of the second switch, changing its setting. The rear axles of car number 3 were switched onto a parallel track, and the entire car was thereby thrown into the piers supporting a 300-tonne (300-long-ton; 330-short-ton) roadway overpass, destroying them.

Car number 4, likewise derailed by the violent deviation of car number 3 and still travelling at 200 kilometres per hour (125 mph), passed intact under the bridge and rolled onto the embankment immediately behind it, striking several trees before coming to a stop. Two Deutsche Bahn railway workers who had been working near the bridge were killed instantly when the derailed car crushed them. The breaking of the car couplings caused the automatic emergency brakes to engage and the mostly undamaged first three cars came to a stop.
Bridge collapse

The front power car and coaches one and two cleared the bridge. Coach three hit the bridge, which began to collapse. Coach four cleared the bridge, moved away from the track, and hit a group of trees. The bridge pieces crushed the rear half of coach five. The restaurant coach, six, was crushed to a 15-centimetre (6 in) height. With the track now obstructed completely by the collapsed bridge, the remaining cars jackknifed into the rubble in a zig-zag pattern: Cars 7, the service car, the restaurant car, the three first-class cars numbered 10 to 12, and the rear power car all derailed and slammed into the pile.[1][time needed] The resulting mess was likened to a partially collapsed folding ruler. An automobile was also found in the wreckage. It belonged to the two railway technicians and was probably parked on the bridge before the accident.[1][time needed]

Separated from the rest of the carriages, the detached front power car coasted for a further three kilometers (two miles) until it came to a stop after passing Eschede railway station.
Front power car 401 051 at Munich in August 2007. The partially derailed front power car continued to travel down the track until it came to a halt a short distance after Eschede railway station. Having sustained only minor damage, it was repaired and returned to service

The crash produced a sound that witnesses later described as "startling", "horribly loud", and "like a plane crash". Nearby residents, alerted by the sound, were the first to arrive at the scene. Erika Karl, the first person to walk into the accident scene, photographed the accident site. Karl said that, upon hearing the noise, her husband believed initially that the accident was an aircraft accident. After the accident, eight of the ICE carriages occupied an area slightly longer than the length of a single carriage.[1][time needed]

At 11:02, the local security officer declared an emergency; at 11:07, as the magnitude of the disaster quickly became apparent, this was elevated to "major emergency"; and at 12:30 the Celle district government declared a "catastrophic emergency" (civil state of emergency). More than 1000 rescue workers from regional emergency services, fire departments, rescue services, the security officer and army were dispatched. Some 37 emergency physicians, who happened to be attending a professional conference in nearby Hanover, also provided assistance during the early hours of the rescue effort, as did units of the British Forces Germany.

While the driver and many passengers in the front part of the train survived with minor to moderate injuries, there was little chance of survival for those in the rear carriages, which crashed into the concrete bridge pile at a speed of 200 km/h (120 mph). Including the two railway workers who had been standing under the bridge, 101 people died. ICE 787 had passed under the bridge going in the opposite direction (on the Hamburg to Hanover route) only two minutes earlier.

By 13:45 authorities gave emergency treatment to 87 people. 27 of the most severely injured passengers were airlifted to hospitals

Causes

Remains of a VW Golf Variant, belonging to the two railway workers killed in the crash, were found beneath the debris of the crashed ICE. Media first speculated that the train had derailed after a collision with the car,[3] a circumstance that caused a train to jackknife in the Ufton Nervet rail crash six years later; this theory was quickly dismissed, however, as the front power car did not receive any damage at all, having continued to coast down the track until it passed the next station.
Wheel design

The ICE 1 trains were originally equipped with single-cast wheelsets, known as Monobloc wheels. Once in service it soon became apparent that this design could, as a result of metal fatigue[citation needed] and out-of-round conditions, result in resonance and vibration at cruising speed. Passengers noticed this particularly in the restaurant car, where there were reports of loud vibrations in the dinnerware and of glasses "creeping" across tables.

Managers in the railway organisation had experienced these severe vibrations on a trip and asked to have the problem solved. In response engineers decided that to solve the problem, the suspension of ICE cars could be improved with the use of a rubber damping ring between the rail-contacting steel tyre and the steel wheel body. A similar design had been employed successfully in trams (known as resilient wheels), at significantly lower speeds. This new wheel, dubbed a "wheel-tyre" design, consisted of a wheel body surrounded by a 20-millimetre (0.79 in) thick rubber damper and then a relatively thin metal tyre. The new design was not tested at high speed before it was made operational, but was successful at resolving the issue of vibration at cruising speeds.

At the time, no facilities existed in Germany that could test the actual failure limit of the wheels, and so complete prototypes were never tested physically.[citation needed] The design and specification relied greatly on available materials data and theory. The very few laboratory and rail tests that were performed did not measure wheel behaviour with extended wear conditions or speeds greater than normal cruising. Nevertheless, over a period of years the wheels proved themselves apparently reliable and, until the accident, had not caused any major problems.

In July 1997, nearly one year before the disaster, Üstra, the company that operates Hanover's tram network, discovered fatigue cracks in dual block wheels on trams running at about 24 km/h (15 mph). It began changing wheels before fatigue cracks could develop, much earlier than was legally required by the specification. Üstra reported its findings in a warning to all other users of wheels built with similar designs, including Deutsche Bahn, in late 1997. According to Üstra, Deutsche Bahn replied by stating that they had not noticed problems in their trains.[1][time needed]

The Fraunhofer Institute for Structural Durability and System Reliability (LBF) in Darmstadt was charged with the task of determining the cause of the accident. It was revealed later that the institute had told the DB management as early as 1992 about its concerns about possible wheel-tyre failure.

It was soon apparent that dynamic repetitive forces had not been accounted for in the statistical failure modelling done during the design phase, and the resulting design lacked an adequate margin of safety. The following factors, overlooked during design, were noted:

   The tyres were flattened into an ellipse as the wheel turned through each revolution (approximately 500,000 times during a typical day in service on an ICE train), with corresponding fatigue effects.
   In contrast to the monobloc wheel design, cracks could also form on the inside of the tyre.
   As the tyre became thinner due to wear, the dynamic forces were exaggerated, resulting in crack growth.
   Flat spots and ridges or swells in the tyre dramatically increased the dynamic forces on the assembly and greatly accelerated wear.

Failing to stop the train permitted the wheel to disintegrate, resulting in a catastrophic series of events. Had the train been stopped immediately it is unlikely that the subsequent events would have occurred.

Valuable time was lost when Dittmann tried to warn the train crew about the large piece of metal coming up through the floor, instead of pulling the emergency brake himself. The train manager refused to stop the train until he had investigated the problem himself, saying this was company policy. This decision was upheld in court, absolving the train manager of all charges. Given that he was a customer service employee and not a train maintainer or engineer, he had no more authority to make an engineering judgment about whether or not to stop the train than the passenger anyway.
Maintenance

About the time of the disaster, the technicians at Deutsche Bahn's maintenance facility in Munich used only standard flashlights for visual inspection of the tyres, instead of metal fatigue detection equipment.[4] Previously, advanced testing machines had been used; as the equipment generated many false positive error messages, however, it was considered unreliable and its use was discontinued. During the week prior to the Eschede disaster, three separate automated checks indicated that a wheel was defective. Investigators discovered, from a maintenance report generated by the train's on-board computer, that two months prior to the Eschede disaster, conductors and other train staff filed eight separate complaints about the noises and vibrations generated from the bogie with the defective wheel; the company did not replace the wheel. Deutsche Bahn said that its inspections were proper at the time and that the engineers could not have predicted the wheel fracture.[1][time needed]
Other factors

The design of the overbridge may have also contributed to the accident because it had two thin piers holding up the bridge on either side, instead of the spans going from solid abutments to solid abutments. The Granville train disaster of 1977 had a similar weakness in its bridge. The bridge built after the disaster is a cantilevered design and does not have this vulnerability. Though it is practical to mandate that new bridges should be designed to resist collapsing in the event of an impact, it would be of questionable practicability to mandate the replacement of all existing bridges that used the old design.

Another contributing factor to the casualty rate was the use of welds in the carriage bodies that "unzipped" during the crash.[5]

In summary, though the disintegrated resilient wheel was the root cause of the accident, the damage was as severe as it was due to a number of factors, including the proximity to the bridge and flipping point, as well as the position of the wheel on the front-end train car, leading to a large number of cars derailing.

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6 Big Bayou Canot rail accident

The Big Bayou Canot rail accident was the derailing of an Amtrak train on the CSXT Big Bayou Canot bridge in southwestern Alabama, United States, on September 22, 1993. It was caused by displacement of a span and deformation of the rails when a tow of heavy barges collided with the rail bridge eight minutes earlier. 47 people were killed and 103 more were injured. [1] To date, it's both the deadliest train wreck i Amtrak's history and the worst rail disaster in the United States since the 1958 Newark Bay, New Jersey rail accident in which 48 lives were lost.

Events

Immediately prior to the accident, a barge being pushed by the towboat Mauvilla (owned and operated by Warrior and Gulf Navigation of Chickasaw, Alabama) had made a wrong turn on the Mobile River and entered the Big Bayou Canot, an un-navigable channel of water crossed by a CSX Transportation rail bridge. The towboat's pilot, Willie Odom, was not properly trained on how to read his radar and so, due to the very poor visibility in heavy fog and his lack of experience, did not realize he was off course. The boat also lacked a compass and a chart of the waters. [2] Odom believed that he was still on the Mobile River and had identified the bridge in the radar as another tug boat. [3] After the investigation, he was not found to be criminally liable for the accident. [3]

The bridge was struck by the Mauvilla at about 2:45 am. The span had been designed to rotate so it could be converted to a swing bridge by adding suitable equipment. No such conversion had ever been performed but the span had not been adequately secured against unintended movement. The collision forced the unsecured end of the bridge span approximately three feet out of alignment and severely kinked the track. [4][5]

At 2:53 a.m.,[1] Amtrak's Sunset Limited train, powered by three locomotives (one GE Genesis P40DC number 819 in the front and two EMD F40PHs, numbers 262 and 312) en route from Los Angeles, California to Miami, Florida with 220 passengers and crew aboard, crossed the bridge at around 70 miles per hour (113 km/h) and derailed at the kink. The first of its three locomotives slammed into the displaced span, causing that part of the bridge to collapse into the water beneath. The lead locomotive embedded itself nose-first into the canal bank and the other two locomotives, together with the baggage car, dormitory car and two of the six passenger cars, plunged into the water. The locomotives' fuel tanks, each of which held several thousand gallons of diesel fuel, ruptured upon impact,[1] resulting in a massive fuel spill and a fire. Forty-seven people, 42 of whom were passengers, [1] were killed, many by drowning, others by fire/smoke inhalation. Another 103 were injured. The towboat's four crew members were not injured. [1] At the time of the derailment, the lead locomotive, number 819, had been in service with Amtrak for only twenty days. [6]

Despite the displacement of the bridge, the continuously welded rails did not break. As a result, the track circuit controlling the bridge approach block signals remained closed (intact) and the nearest signal continued to display a clear (green) aspect. Had one of the rails been severed by the bridge's displacement, the track circuit would have opened, causing the approach signal to display a stop (red) aspect and the preceding signal an amber (caution) approach indication. This might have given the Amtrak engineer sufficient time to stop his train or at least reduce its speed in an effort to minimize the accident's severity.


Fatal delay

An episode of the National Geographic Channel documentary series Seconds From Disaster examined the accident. In addition to corroborating findings of the official accident report, the program revealed that the train had been delayed in New Orleans by repairs to an air conditioner unit and a toilet. This had put it a half-hour behind schedule. If not for this delay, the Sunset Limited would have passed over the Big Bayou Canot bridge 20 minutes before the bridge was hit by the barge.

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7 Meltdown in Chernobyl

Seconds From Disaster - Meltdown in Chernobyl

The Chernobyl disaster (also referred to as Chernobyl or the Chernobyl accident) was a catastrophic nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in Ukraine (then officially the Ukrainian SSR), which was under the direct jurisdiction of the central authorities of the Soviet Union. An explosion and fire released large quantities of radioactive particles into the atmosphere, which spread over much of the western USSR and Europe.

The Chernobyl disaster was the worst nuclear power plant accident in history in terms of cost and casualties. It is one of only two classified as a level 7 event (the maximum classification) on the International Nuclear Event Scale, the other being the Fukushima Daiichi nuclear disaster in 2011. The battle to contain the contamination and avert a greater catastrophe ultimately involved over 500,000 workers and cost an estimated 18 billion rubles.During the accident itself, 31 people died, and long-term effects such as cancers are still being investigated.
The disaster began during a systems test on Saturday, 26 April 1986 at reactor number four of the Chernobyl plant, which is near the city of Pripyat and in proximity to the administrative border with Belarus and the Dnieper River. There was a sudden and unexpected power surge, and when an emergency shutdown was attempted, an exponentially larger spike in power output occurred, which led to a reactor vessel rupture and a series of steam explosions. These events exposed the graphite moderator of the reactor to air, causing it to ignite. The resulting fire sent a plume of highly radioactive fallout into the atmosphere and over an extensive geographical area, including Pripyat. The plume drifted over large parts of the western Soviet Union and Europe. From 1986 to 2000, 350,400 people were evacuated and resettled from the most severely contaminated areas of Belarus, Russia, and Ukraine.According to official post-Soviet data,about 60% of the fallout landed in Belarus.

Russia, Ukraine, and Belarus have been burdened with the continuing and substantial decontamination and health care costs of the Chernobyl accident. A report by the International Atomic Energy Agency examines the environmental consequences of the accident.[8] Another UN agency, UNSCEAR, has estimated a global collective dose of radiation exposure from the accident "equivalent on average to 21 additional days of world exposure to natural background radiation"; individual doses were far higher than the global mean among those most exposed, including 530,000 local recovery workers who averaged an effective dose equivalent to an extra 50 years of typical natural background radiation exposure each.Estimates of the number of deaths that will eventually result from the accident vary enormously; disparities reflect both the lack of solid scientific data and the different methodologies used to quantify mortality

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8 Seconds From Disaster - Inferno in Guadalajara



A series of ten explosions took place on April 22, 1992, in the downtown district of Analco Colonia Atlas in Guadalajara city, Jalisco state, Mexico. Numerous gasoline explosions in the sewer system and fires over four hours destroyed 8 kilometres (5.0 mi) of streets.[1] Gante Street was the most damaged. By the accounting of Lloyd's of London, the reported number of people killed was about 252 people although many estimate that the catastrophe actually caused at least 1000 deaths.[2] About 500 to 600 people were missing,[2] nearly 500 were injured and 15,000 were left homeless. The estimated monetary damage ranges between $300 million and $1 billion. The affected areas can be recognized by the more modern architecture in the areas that were destroyed.[3]


Four days before the explosion, residents started complaining of a strong gas-like smell coming from the sewers which became progressively more pungent over the course of those days. They were experiencing symptoms such as stinging in their eyes and throats; and nausea.[4] Some residents even found gasoline coming out of their water pipes. City workers were dispatched to check the sewers and found dangerously high levels of gasoline fumes. However, the city mayor did not feel it was necessary to evacuate the city because he felt that there was no risk of an explosion.


Chronology of events


Before the explosions, on April 19, Gante Street residents reported a strong stench of gasoline and plumes of white smoke coming out from the sewers to the City of Guadalajara. The next day, workers of the City Council and Civil Protection commenced two days of investigations in Gante Street; they found high levels of gasoline among other hydrocarbons, but announced it was not necessary to evacuate the area. At 10am on April 22, manhole covers in the street began to bounce and columns of white smoke started coming out of them.

At 10:05 on April 22, the first two explosions were recorded, the first on the corner of Calzada Independencia and Aldama Street, and the second at the intersection of Gante and 20 De Noviembre. A minute later the first call was received on the 060 Emergency Line and was forwarded to automatic voice messenger. A third explosion at 10:08 resulted in a bus, belonging to the Tuts Company, being projected through the air on the corner of Gante and Nicolas Bravo. Four minutes later another explosion was registered in Gonzalez Gallo Avenue. At 10:15 factory workers along Gonzalez Gallo Avenue began to evacuate, just before rescue teams and volunteers began to arrive in areas affected by the explosions. At 10:23 the fifth explosion occurred, at the intersection of Gante and Calzada del Ejercito. At 10:29 evacuations began in the Mexicaltzingo neighborhood, two minutes before the sixth explosion was recorded at the intersection of 5 De Febrero and Rio Bravo.

At 10:43 the seventh explosion occurred, at the corner of Ghent Street and Silverio Garcia. Just after more rescue teams arrived in the affected areas, the eighth explosion occurred at 11:02, at the intersection of Rio Nilo Avenue and the Rio Grande. After this explosion the neighborhoods of Atlas, Alamo Industrial, El Rosario, Quinta Velarde and Fraccionamiento Revolución; and the center of the municipality of Tlaquepaque; were evacuated. The last two explosions were at 11:16, one at the intersection of Rio Alamos and Rio Pecos, and the other at González Gallo and Rio Suchiate. In the afternoon, the fear of further tragedies made people across the Guadalajara Metro Area uncover manholes for any remaining gases to escape. Residents of neighborhoods such as Zona Industrial, 18 De marzo, Fresno, 8 De Julio, Ferrocarril, La Nogalera, Morelos, Echeverria, Polanco, 5 de mayo and Miravalle are told to be aware of any unusual events.

After the explosions, there was great panic on April 25 among residents of the neighborhoods 5 De Mayo, el Dean, Echeverría and Polanco; firefighters asked people to avoid lighting any flames, due to a strong smell of gas. It was later confirmed to be a leak in a Pemex pipe.
Investigation

An investigation into the disaster found that there were two precipitating causes:

    New water pipes, made of zinc-coated iron, were built too close to an existing steel gasoline pipeline. The underground humidity caused these materials to create an electrolytic reaction, akin to that which occurs inside a zinc-carbon battery. As the reaction proceeded it eventually caused the steel pipe to corrode, creating a hole in the pipeline that permitted gasoline to leak into the ground and into the main sewer pipe.
    The sewer pipe had been recently rebuilt into a U-shape so that the city could expand its underground metro railway system. Usually sewers are built in a slope so that gravity helps move waste along. In order to get the U-shape to work, an inverted siphon was placed so that fluids could be pushed against gravity. The design was flawed, however. While liquids were successfully pumped through, gases were not, and gas fumes would build up.

Aftermath

In the aftermath, city officials and corporations blamed each other. Some people initially thought a cooking oil manufacturing company was leaking hexane, a flammable liquid similar to (and a component of) gasoline, into the sewers, but this was later found to be erroneous. Numerous arrests were made in an attempt to indict those responsible for the blasts.[6] Four Pemex officials were indicted and charged, on the basis of negligence. Ultimately, however, these people were cleared of all charges.[7]

Many of the survivors that were affected by the explosions started a group called "La Asociacion 22 de Abril en Guadalajara" (the association of April 22 of Guadalajara).[8] This campaign was started by a survivor of the explosions named Lilia Ruiz Chávez, who as a result of the explosions lost her leg as well as her home. She started the group that has a total of 80 members not only because no one was convicted of this preventable incident but also because the victims of this tragedy were not receiving any compensation or assistance due to injuries sustained or loss as a result of the accident. The victims of this tragedy not only lost their homes but also their health and many lost loved ones as well. Although they are aware that no amount of money will bring back their relatives as states Chavez, the tragedy left them unable to care for themselves let alone afford their medication as a consequence of the incident. Chavez as well as the other survivors have been fighting for 24 years now for justice to be served. Because of the constant struggle and pressure from the victims toward Pemex, the company that was initially blamed for the incident, finally agreed to pay out 40 million pesos to the group. Although Pemex claims this is a donation and no way does it mean they are taking blame for the incident.

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