An American Airlines regional jet collided with a U.S. Army Black Hawk helicopter on Jan. 29. Both aircraft plunged into the Potomac River near Reagan Airport.

Now, the U.S. Army Corps of Engineers will focus on retrieving the mangled helicopter, a crucial component in federal authorities' probe as they look to confirm data related to its altitude at the time of the collision,

Authorities say they have identified all but one of the victims of the deadly collision that happened on January 29.