Hundreds of families are in mourning after an American Airlines regional jet collided with a U.S. Army Black Hawk helicopter on Wednesday night, with both aircraft plunging into the Potomac River near Washington,

Sixty-seven people died in a collision between a Bombardier CRJ700 regional jet operated by PSA Airlines and a military Black Hawk helicopter.

Lifting operations are expected to begin today to remove wreckage from the American Airlines plane out of the Potomac River. The process will take three days, according to the U.S. Army Corps. After the jet is recovered, crews will shift to recover the Black Hawk helicopter and associated wreckage, officials said Sunday.