This Thursday, April 18, 2013 aerial photo shows the remains of a nursing home, left, apartment complex, center, and fertilizer plant, right, destroyed by an explosion in West, Texas.

This aerial photo shows the remains of a burned and damaged school following a Wednesday night fertilizer plant explosion in West, Texas, Thursday, April 18.

Police and rescue workers stand near a building which was left destroyed from a massive explosion at a nearby fertilizer plant in the town of West, near Waco, Texas April 18.

Investigators stand amid the aftermath of a massive explosion at a fertilizer plant in the town of West, near Waco, Texas April 18.

This aerial photo shows burned down and damaged homes on Thursday, April 18 following an explosion Wednesday a near by fertilizer plant in West, Texas,

Members of a rescue team watch as divers prepare to retrieve the black box from a partially submerged Lion Air Boeing 737 on April 15, 2013, two days after it crashed while trying to land at Bali's international airport near Denpasar. The pilot and co-pilot of a Lion Air plane that crashed at Bali's airport have passed initial drug tests, an official said on April 15, as investigators probe the causes of the accident that left dozens injured but no fatalities.

A trailer truck driver is rescued from the cab of her truck while it dangles from the Monitor-Merrimac Bridge Tunnel, by Newport News Master Fire Fighter Scott Dye on April, 8, in Newport News, Va.

The driver of a tractor-trailer is stuck inside the cab of her truck that is dangling from the Monitor-Merrimac Bridge Tunnel on Interstate I-664 on April 8, in Newport News, Va.

A policeman stands next to the accident site where two helicopters crashed near the Olympic stadium in Berlin on March 21.

Police officers work at the scene where two police helicopters crashed near the Olympic stadium in Berlin.

The wreckage of a police helicopter is seen near the Olympic stadium in Berlin.

Firemen try to repel toxic gases with water at a plant of Kraft Foods in Bad Fallingbostel, northern Germany, in the early morning of Oct. 16.

An evacuated resident waits in the Heidmarkhalle after a chemical accident at a Kraft Foods plant in Bad Fallingbostel, Germany, Oct. 16.

Officials and locals gather around the fallen compartments of Doon Express, a passenger train which derailed in Jaunpur, Uttar Pradesh state, India on Thursday. According to news reports at least five people were killed and about fifty others injured after the passenger train which was traveling from Howrah station, near Calcutta city, to Dehradun in the state of Uttarakhand derailed.

A volunteer extends a helping hand to a trapped passenger, who's hand can be seen, inside a fallen compartment of Doon Express, a passenger train which derailed.

Officials inspect the wreckage of the Doon Express.

Soldiers unload coffins of children and teachers who were killed in a deadly bus crash in Switzerland, at the military airport of Melsbroek, Belgium, on March 16. A coach accident in Switzerland on Wednesday left 28 dead, including 22 children traveling home after a skiing holiday.

Children of primary school 'De Speling' in Lommel form a circle around a heart drawn with chalk on March 16 during a minute of silence at the 't Stekske primary school in Lommel for the victims of the March 13 bus crash near the town of Sierre in southern Switzerland. Twenty-eight people died in the accident, including 22 children from two schools of Lommel and Heverlee, returning to Belgium from a skiing holiday. Belgians observed a minute of silence and church bells tolled across the grieving nation on March 16 as the bodies of the victims were flown home.