Comair sued the Federal Aviation Administration on Thursday, saying the agency was negligent in having only one air traffic controller on duty last year when a plane took off from the wrong runway and crashed. The accident killed 49 people.

The lawsuit seeks unspecified damages.

The Comair commuter jet mistakenly turned onto a too-short runway in the dark, struggled to get airborne and went down in a field Aug. 27 at Lexington's Blue Grass Airport. The co-pilot was the only survivor.

A week earlier, the taxi route leading to the correct, longer runway had been changed during a construction project.

Comair claims the FAA should have staffed the tower with two controllers. The lone controller on duty that morning had turned away to do some administrative tasks before Comair Flight 5191 tried to take off.

The FAA had no immediate comment.

Comair, a subsidiary of Delta Air Lines Inc., operates 850 flights to 108 cities daily. Both airlines filed for bankruptcy protection last year.

Comair claimed in a previous lawsuit that the FAA failed to inspect and approve construction along the taxi route. That lawsuit was dismissed Tuesday.