Rescue workers tend to the injured after an Amtrak passenger train derailed in Kensington, Maryland, a Washington, D.C., suburb Monday. The train was headed for Washington, D.C., from Chicago. Six of the train's 13 cars lay on their side.

　　Investigators recovered data recorders from the wreckage of the train that they say should provide clues to why the train jumped off the tracks, leaving 97 passengers injured.

　　Six people were trapped in the cars, but all were freed within an hour. They were reported to be in critical condition.