The Alpine village of Galtur, an avalanche buries 57 people in the snow. 31 of them die. But why did the avalanche occur in the first place? Were careless villagers to blame?

January 1989. British Midland Airways Flight 092, a Boeing 737, is landing at Kegworth, United Kingdom, when it crashes on the M1 motorway, killing 47 people. What went wrong? The B-737 is the most widely-used airliner in the world. Could mechanical failure be to blame? Perhaps human error? Or even sabotage?

Mount St. Helens, in the countryside of Washington State, has been dormant for 123 years. But on May 1980, it suddenly erupts, killing 57. Why couldn't they predict it?

On March 1987, the British Car Ferry Herald of Free Enterprise capsizes off Zeebrugge killing 193. Why did this happen? Was it just a terrible blunder? Or something worse?

On 17 January 1995, the Japanese city of Kobe was rocked by the Great Hanshin Earthquake, which destroyed buildings and killed over 1000 people and left thousands homeless. Why couldn't the top of the art equipment predict a disaster of this magnitude?

On 19 July 1989, the pilots of United Airlines Flight 232 are shocked to learn they have lost all control of the DC-10 after an engine failure and make an emergency landing at Sioux City, Iowa, but in a dramatic crash, the aircraft breaks apart and catches fire with 111 lives lost out of the 285 on board. Why did the engine fail?

Bali, located in Indonesia, is one of the most popular resorts in the world. But 202 die on the night of October 12, 2002, Muslim terrorists detonate several bombs in local nightclubs. Its the horror of 9/11 all over again.

Hotel New World, budget hotel located in Singapore's Little India, collapses on 15 March, 1986. After a 7 day rescue operation, 17 people are rescued but 33 perish. Why did the hotel collapse? Was it sabotage? Or was it faulty maintenance?

17 July 1996. TWA Flight 800 leaves New York for Paris. Only 12 minutes into the flight, it explodes catastrophically, breaks in half, then plummets into the sea killing all 230 people on board. There was no mayday call from the crew. Rumours spread that the B-747 was downed by a misguided navy missile, sparking the biggest accident investigation in history.

In what was no doubt the worst rail incident in French history, a runaway train derails at Gare De Lyon Station, France, killing 56 people. Why did the train crash so horribly? Who is to blame?

When the zeppelin Hindenburg catches fire at Lakehurst, 35 of the 97 on board and one member of the ground crew are killed. Was the most infamous airship disaster caused by a ticking time bomb smuggled on board? Or was the Hindenburg itself a ticking time bomb?

The Humberto Vidal Shoe Store was just like any other. But one day in Puerto Rico, a gas explosion kills 33 and injures 69 people.

The DH Comet is the first jet airliner and the pride of the British Overseas Airways Corporation. But on January 10, 1954, BOAC Flight 781, enroute from Rome to London, explodes catastrophically and crashes, killing 35 people. The investigation begins, but when South African Airways Flight 201 crashes exactly the same way taking another 21 lives, all Comets are grounded and the investigation takes a step forward.

American Airlines Flight 191, a DC-10, leaves Chicago. But when the engine falls off, the plane stalls and crashes killing 273 people. The investigators discover a shocking secret which will turn the aviation world upside down.

The Texas BP oil refinery is the third largest in America producing more than 437,000 barrels per day. Workmen are starting a routine day, then, and explosion rocks the structure with the death of 15. What went wrong?

On 3 April 1974, the most violent outbreak of tornadoes in history struck. The well-named "Super Outbreak" produces 148 twisters over 13 American states and in Ontario, Canada destroying thousands of homes and over 5,000 people die. How did a single storm form the 1974 "Super Outbreak" tornadoes?

On a cold winter day in 1986, space shuttle Challenger takes off from Cape Canaveral to start Mission 51-L. 73 seconds later, Challenger's boosters explode and send it into the ocean in pieces. What happened? Was a fault to blame? Or was there ice on the shuttle?

On the Caribbean island of Montserrat is the Soufrière Hills volcano. Nearby is Plymouth, the island's capital. In 1995, Soufrière Hills came to life and spewed ash over the island. Everyone is evacuated to the north of Montserrat. Two years on, the eruptions get worse and in 1997, Soufrière Hills erupts violently. Pyroclastic flows rage down the mountain and destroy Plymouth and Bramble Airport, killing 23 people. It generates a small tsunami. People crowd onto ships to escape their home, knowing it's been destroyed.

On September 11, 2001 two aircraft are deliberately flown into two buildings of the World Trade Center and one is flown into the Pentagon. Another crashes in a field in rural Pennsylvania.

On December 7, 1941 Japanese forces attack United States military installations in and around Pearl Harbor, thus bringing the US into World War II.

On October 5, 1999 two trains collide at Ladbroke Grove junction near London's Paddington station after the driver of one fails to stop his train at a red signal.

The Cavalese cable car disaster of 1998 (as distinct from a cable car disaster in the same location in 1976), occurred on 3 February 1998 near the Italian town of Cavalese, a ski resort located in the Dolomites, some 40 km north-east of Trento. The disaster, which led to the death of 20 people, occurred when a U.S. military plane cut a cable supporting a gondola of an aerial tramway.

On December 2, 1984 in Bhopal, India, a toxic gas leak at a Union Carbide chemical plant results in the deaths of 3,000 people.

On August 6, 2011, a U.S. Boeing CH-47 Chinook was shot down while transporting a quick reaction force attempting to reinforce an engaged unit of Army Rangers in Wardak province, west of Kabul, Afghanistan. The resulting crash killed all 38 people on board.

On October 3–4, 1993, what should have been a simple snatch and grab operation for the US Army in Somalia turns into a battle that kills 18 US Rangers and around 1,000 Somali civilians.