The National Transportation Safety Board has interviewed the air-traffic controller who was working at the time of the midair collision, board member Todd Inman said, adding that the interviews have been ongoing throughout the day.

On a fall afternoon, a Boeing passenger jet had just been cleared for takeoff at Reagan National Airport when the pilot saw a Bell helicopter lift off in a direction that would cross the plane’s path. The airplane pilot aborted the takeoff, overrunning the runway before coming to a stop on a grassy strip just 130 feet from the Potomac River.