This aerial photo shows the wreckage of the Asiana Flight 214 airplane after it crashed at the San Francisco International Airport in San Francisco, Saturday, July 6, 2013. (Photo by Marcio Jose Sanchez/AP Photo)

A burning train wagon is seen after an explosion at Lac Megantic, Quebec, July 6, 2013. A large swath of Lac Megantic was destroyed Saturday after a train carrying crude oil derailed, sparking several explosions and forcing the evacuation of up to 1,000 people. (Photo by Mathieu Belanger/Reuters)

Kent Josephso organizes his 8mm tracer rounds during the Big Sandy Shoot in Mohave County, Arizona March 23, 2013. The Big Sandy Shoot is the largest organized machine gun shoot in the United States attended by shooters from around the country. Vintage and replica style machine guns and cannons are some of the weapons displayed during the event. Picture taken March 22, 2013. (Photo by Joshua Lott/Reuters)

A man walks beside a “Wrinkles Of The City” creation near the Berlin cathedral in Berlin April 19, 2013. (Photo by Fabrizio Bensch/Reuters)

A woman sits in a cell at the Los Angeles County Women's jail in Lynwood, California April 26, 2013. (Photo by Lucy Nicholson/Reuters)

A demonstrator is detained during May Day rallies in Santiago May 1, 2013. (Photo by Ivan Alvarado/Reuters)

The Eiffel Tower is illuminated during the traditional Bastille Day fireworks display in Paris, July 14, 2013. (Photo by Fred Dufour/AFP Photo)

Coffins are lined up near the wreckage of the bus, on July 29, 2013. (Photo by Salvatore Laporta/Associated Press)