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.

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

Crews were on scene on the Potomac River on Monday to retrieve the submerged wreckage of an airliner and an Army helicopter that collided midair last week in the deadliest US air disaster since 2001.