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What investigators revealed about the plane crash in D.C.
7m 57s
Investigators are trying to determine why a U.S. Army helicopter and an American Airlines passenger jet collided in the air as the plane was trying to land in Washington. Officials believe everyone on board both aircraft died when they crashed into the Potomac River. It's the deadliest air crash in the U.S. in more than two decades with 67 presumed dead. John Yang reports.