Petty Officer 1st Class Brandon Giles/ U.S. Coast Guard via Getty Images(WASHINGTON) -- Hundreds of families are in mourning ...

Crews are on the scene on the Potomac River to retrieve the submerged wreckage of an airliner and an Army helicopter that collided midair in the deadliest U.S. air disaster since 2001.

Flight 5342's black box put its altitude at 325ft at the time of collision - over 100ft higher than choppers are allowed to ...