WASHINGTON: Officials have positively identified 55 of the 67 people killed in Wednesday's midair collision between an American Airlines passenger jet and a military helicopter over the Potomac River, Washington, DC Fire Chief John Donnelly said on Sunday.

The Army Corps of Engineers is surveying and preparing to begin significant salvage operations on Monday to remove the wreckage from the river.

Wreckage is being moved to a hangar at Washington Reagan National Airport. Much of the Potomac River remains off limits to all vessels except authorized boats.