The pilots of the Comair CRJ200 that crashed into a field while taking off from Lexington, Ky., Blue Grass Airport early Sunday morning used the wrong runway, National Transportation Safety Board Member Deborah Hersman confirmed in an evening briefing.

The aircraft apparently was cleared to depart from Runway 22, the main runway with a length of 7,003 ft. However, it lined up on the shorter general aviation runway, 26, which is 3,500 ft. in length, insufficient for the fully loaded jet to become airborne.

The CRJ crashed through a perimeter fence and came to rest approximately 1 mi. beyond the runway, killing 49 of 50 people onboard. The first officer survived and remains in critical condition. The sun had yet to rise but conditions at the time of the accident were described as clear. When rescuers reached the crash site, the aircraft largely was intact but was in flames. The CVR and FDR have been recovered.

Flight 5191 was bound for Atlanta. Comair operates as Delta Connection and is a wholly owned subsidiary of Delta Air Lines. Both are operating under Chapter 11 bankruptcy protection.

The aircraft, N431CA (tail no. 7472) was acquired from Bombardier in January 2001 and had a clean maintenance record, Comair CEO Don Bornhorst told reporters. It had 14,536 flight hr. and 12,048 cycles. "On behalf of everyone at Comair, I cannot adequately express to you our sadness about this accident and our deep concern for everyone involved," Bornhorst said.

It is the worst US airline accident since the November 2001 crash of an American Airlines A300 that resulted in the deaths of 251 passengers, nine crewmembers and five people on the ground. It is Comair's second fatal accident. An Embraer Brasilia turboprop crashed on approach to Detroit Metro in January 1997, killing 26 passengers and three crew.