Officials with the National Transportation Safety Board (NTSB) are still trying to determine what caused yesterday's derailment of an Amtrak passenger train outside of Washington, D.C. A spokesperson for the NTSB said investigators are now focusing on the train's two event recorders, devices similar to an airplane's "black box", to provide information on the speed of the train as well as if it was braking or accelerating shortly before it derailed.

According to the Safety Board, initial findings revealed that the train, the Capitol Limited, was operating properly. A spokesperson for CSX Corporation, the owner of the stretch of track in Kensington, Maryland, told the NTSB that the track was inspected less than 24 hours before the accident occurred. CSX also informed investigators that a freight train had passed through the area 45 minutes before the Amtrak train derailed. The NTSB said the investigation might take several months to complete. Over 100 passengers were injured, six seriously, in the accident.