An American Airlines regional jet went down in the Potomac River near Ronald Reagan Washington National Airport.

Sixty passengers and four crew members from the plane and three Black Hawk helicopter personnel are feared dead as a recovery mission is underway.

DALLAS — Investigators from the National Transportation Safety Board will likely be studying three main elements as they try to pinpoint the cause of the mid-air collision between American Airlines Flight 5342 and the U.S. Army helicopter on Wednesday night.