Crews using a crane lifted the first pieces of wreckage from the downed American Airlines regional jet from the Potomac River on Monday morning as rescue workers sought to recover all 67 bodies from the crash site near Ronald Reagan National Airport.

Six days after the plane and an Army helicopter collided in a fiery crash that left no survivors, a red crane lifted what appeared to be a chunk of the jet out of the water.

The snarled metal resembling an engine emerged from the gray water shortly before 10 a.m., beginning the process of extracting the airplane and helicopter that once carried passengers, crew members and soldiers.

Crews in hard hats and high-visibility jackets stood nearby on the barge, water lapping at its base. A couple of small police boats with blue flashing lights were stationed nearby as daily routines continued: Cars rumbled down the nearby highway; the Metro squeaked past; passenger planes roared upon take-off.

Col. Francis Pera, the Baltimore district commander for the U.S. Army Corps of Engineers, which is helping to oversee the work, said Sunday that the crew will carefully bring what is left of the plane to the surface with the help of Navy salvagers and dive teams. Officials said it could take up three days to complete and will stop if human remains are found.

Authorities said 11 more bodies were recovered Saturday, bringing to 55 the total number of victims found. There were 60 passengers and four crew members aboard American Eagle Flight 5342 and three soldiers on the Black Hawk helicopter.

After the civilian craft is out of the water, officials said they will turn to removing the Black Hawk helicopter. By Feb. 12, officials said they should have debris elsewhere in the river removed.

The cause of the crash is under investigation by the National Transportation Safety Board. Questions include staffing at the airport control tower and the elevation and position of the Black Hawk, which was performing a night training flight near the busy airport.

The Washington Post has reported that staffing levels were “not normal” on the night of the crash, and data from the Federal Aviation Administration shows the airport is three certified professional controllers below its staffing target of 28.

The NTSB said Saturday that data from the commercial jet’s recorder indicated a “verbal reaction” on board before the plane’s nose slightly lifted upward. Officials said they were analyzing the data recorder from the helicopter, hoping to learn its precise altitude and whether its crew members were wearing night vision goggles.