Some major US airports had less than 60% of their staffing targets filled with fully certified controllers in recent years, CNN review finds

In the immediate aftermath of the deadly collision between an Army Blackhawk helicopter and an American Airlines flight over Washington D.C., people are searching for answers. The direct cause of the Wednesday night collision,

The moments before and after a crash between an American Airlines passenger jet and a military helicopter are detailed in air traffic control audio.

A preliminary safety report from the Federal Aviation Administration reportedly found that air traffic control staffing was abnormally low at Ronald Reagan Washington National Airport on the evening of Wednesday, Jan. 29, according to The New York Times, which obtained a copy of the report.

When aircraft volume goes down, a supervisor can make the decision to combine two controller positions into one position, which happens routinely, according to a source with direct knowledge.

Control tower staffing was “not normal” at the time of the country's worst aviation disaster in a generation. One air traffic controller was doing work normally assigned to two people in the tower at Reagan National when the collision happened,

Fox News' Mark Meredith provides details on the investigation into the midair collision between an Army helicopter and a passenger jet that resulted in dozens of deaths and the efforts to recover wreckage from the Potomac River.