Buffalo, N.Y. ? Relatives of a passenger killed when a commuter plane crashed into a house outside Buffalo have sued Continental Airlines and the flight’s operators, claiming the aircraft had inadequate deicing equipment and an improperly trained crew.

The lawsuit, filed Thursday in federal court in Buffalo, appears to be the first litigation spawned by the Feb. 12 crash in Clarence.

Continental Connection Flight 3407 plunged from the sky in icy weather, killing one occupant of the home and all 49 people aboard the plane.

Investigators have not determined a cause, but ice has been mentioned as a possibility, as well as the crew’s actions.

The family of crash victim Susan Wehle, 55, of Amherst, N.Y., alleges negligence and wrongful death and seeks unspecified damages.

The suit names Continental Airlines, based in Houston; Pinnacle Airlines of Memphis, Tenn., and a subsidiary operating the flight, Colgan Air of Manassas, Va.; and Bombardier Aerospace, based in Montreal, which made the Dash 8 Q400 aircraft.

Pinnacle, Continental and Bombardier declined Friday to comment on the lawsuit, filed by aviation disaster specialists Baum, Hedlund, Aristei & Goldman of Los Angeles.

Colgan Air previously defended its training programs and the pilot after investigators said they would look into whether the crew overreacted to a sensor indicating the plane, flying on autopilot, was slowing down dangerously.

On its Web site, Colgan calls the Q400 “a sophisticated, highly capable aircraft that is designed for cold-weather operations.”