Runway operations at the airport are expected to resume at 11 a.m. "The NTSB will lead the investigation. We are working with local officials and will provide any additional information once it becomes available," McLendon said. A source briefed on the search-and-rescue operation described a gruesome scene with large numbers of bodies recovered.

Investigators searching for wreckage from last week’s deadly midair collision between a US military Black Hawk helicopter and an American Airlines plane near Washington, DC, conducted an overnight scan of the Potomac River where the aircraft fell using advanced imaging technology to map the riverbed and locate debris.

All of the plane and chopper wreckage has been fished from the icy Potomac River, as the National Transportation Safety Board continues to investigate the Jan. 29 mid-air crash that killed 67 people.