Concerns that a deadly collision could occur at Reagan National Airport had long been building. But attempts to draw attention to potentially dangerous conditions sometimes went unheeded.

Remains of 55 of the 67 victims have been recovered, officials said on Sunday as they prepared to lift the wreckage of the jet out of the Potomac River on Monday.

Commercial planes have technology that helps prevent crashes — but it has limitations, which was highlighted by the accident in Washington.

The plane had been cleared to land on Reagan National Airport’s main runway. But in the final moments of the flight, air traffic control asked the pilot to land on a separate, intersecting runway.

The storm caused thousands of flights and dozens of train trips to be delayed or canceled. At Ronald Reagan National Airport in Washington, all runways were closed Monday evening.