What appears to be an aircraft engine belonging to American Airlines Flight 5432 was lifted out of the Potomac River on Monday morning, beginning the complex job of removing the last of the wreckage after a military helicopter collided with it and crashed last Wednesday.

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.

Salvage crews have recovered an engine and large pieces of fuselage and are working to retrieve a wing from wreckage of last week’s midair collision near Washington’s Reagan National Airport

Officials said the bodies of several victims remain in the plane's fuselage and their "dignified" removal is a main priority.

Black boxes from both the airplane and helicopter involved in last week’s deadly crash have been recovered by the NTSB as salvage crews continue to pull the wreckage from the Potomac River. NBC News Correspondent Aaron Gilchrist reports from Arlington,

Salvage crews have removed from the Potomac River a large part of the commercial jet that was involved in a deadly midair collision with a military helicopter last week.