Two U.S. Airways planes were evacuated Sunday morning at Reagan National Airport, after they clipped each other’s wings, officials say. No serious injuries were reported.

A U.S. Airways Airbus A319 headed to LaGuardia Airport and a smaller U.S. Airways Express regional jet on the way to Rochester, N.Y. were at the north side of the airport waiting for their turn at the runway when the collision happened, Courtney Prebich, a representative for the Metropolitan Washington Airports Authority said, according to the Associated Press.

U.S. Airways representative Andrea Rader says the smaller jet was taxiing to the runway when it clipped the wing of the larger aircraft. She also added that it was unclear why the planes collided.

Emergency response vehicles evacuated 63 passengers from both planes onto buses that took them to the terminal, where they were booked onto later flights. No serious injuries were reported, although one passenger complained of back pain and was taken to a hospital for examination, Prebich said.

Damage to the planes was minor and no other delays resulted from the accident, the Airport's officials said.

The National Transportation Safety Board is currently investigating the cause of the accident and will declare the results of its investigation as soon as possible.