An F-16 jettisoned two 500-pound bombs and two fuel tanks during an in-flight emergency, causing an explosion at Hill Air Force Base, base and police officials said.
Col. Scott J. Zobrist said the pilot ran into trouble after taking off Thursday afternoon and had to return to the base about 30 miles north of Salt Lake City.
He said the pilot had to drop the munitions and tanks to lighten the jet's load.
Zobrist said it appears one bomb hit an empty tin shack on base. He said there were no injuries and the plane landed safely.
Zobrist said the two fuel tanks are accounted for and the incident is contained to the base.
Emergency teams are looking to make sure there are no munitions left that could explode.
Capt. Kenny Payne, of Davis County sheriff's office in Farmington, Utah, told NBC News there was an in-flight emergency aboard the F-16.
Utah Highway Patrol Trooper Cameron Roden said Interstate 15 was closed briefly in both directions for a stretch between Sunset and Roy near the base.
A fire from the explosion was extinguished and there were no reports of injuries.
Cause of the in-flight emergency was unknown, Payne said.
The Standard-Examiner in Ogden reported that power at the base was knocked out. Aerial photos on KSL-TV showed an area of blackened grass and two emergency vehicles at the scene.