Salvage crews have recovered the last large pieces of aircraft wreckage from the Potomac River on Thursday and are focusing on collecting small pieces from the crash site where 67 died.

Divers and salvage workers are adhering to strict protocols and will stop moving debris if a body is found, Col. Francis B. Pera of the Army Corps of Engineers said Sunday. The “dignified recovery” of remains takes precedence over all else, he said.

The U.S. Army Corps of Engineers says crews have successfully taken all major pieces of wreckage from the D.C. plane crash out of the Potomac River. The announcement came Thursday evening, just a day after the remains of all 67 victims killed in the midair collision were recovered and positively identified,