Two people were injured Sunday morning when an airport catering truck overran a barricade at Minneapolis-St. Paul International Airport.

The LSG Sky Chefs truck fell to a lower level, blocking a tunnel that led to the airfield and Terminal 1 about 11:30 a.m. Sunday, according to airport spokesman Patrick Hogan.

No one knows why the truck took a nose-dive, Hogan said. It took more than five hours to get the truck horizontal again, and outside help had to be brought in. Air traffic was not affected, Hogan said.

The driver and passenger were able to get out of the van and were taken to the hospital with injuries that weren’t life-threatening.

There have been accidents before, Hogan said, but “this is the first one we’ve had to my knowledge where the vehicle has actually gone over the barrier and into the tunnel roadway below.”