Two major accidents along I-15 Saturday created huge headaches for motorists who were caught in long traffic backups.

The first happened about 11 a.m. when a semitrailer hauling an empty fuel silo failed to clear the 800 North overpass by 2 feet. The silo wrapped around the front I beam of the bridge and forced the closure of that section of freeway for more than three hours.

All northbound traffic was diverted along I-215. Utah Highway Patrol Sgt. Jason Hunter said the overpass was also closed to traffic, but the Utah Department of Transportation determined the structure was stable enough to have vehicles travel beneath it.

The driver of the truck said he had failed to stay on the route designated for his rig by the Utah Port of Entry.

"We got off on one wrong ramp, and you can't exactly do a U-turn or jump off at any exit with something this big," said the Box River Trucking employee, who declined to give his name.

The semitrailer was hauling a diesel-fuel silo from Denver to Corinne. Officials estimate the 30,000-gallon silo weighed 13,000 pounds and was more than 18 feet tall when it was resting on the trailer. Hunter said the clearance beneath the bridge was 15 feet, 9 inches.

As crews removed the trailer, the silo remained wrapped around the I beam on the bridge, hovering some 10 inches above the ground. A backhoe attached with a fork lift was brought on scene to lift and shimmy the silo free from the beam. It eventually fell, booming hollowly when it hit the road.

Citations are pending an investigation of the accident, Hunter said.

While that mess was being cleaned up, a semitrailer tipped onto its side in Utah County after hitting the center concrete barrier.

About 2:20 p.m., a semitrailer was northbound on I-15 near the Alpine exit when a car that had just entered the freeway lost control for an unknown reason and hit the front end of the semitrailer, said UHP Sgt. Blaine Robbins. The impact affected the truck's steering axle, causing the large vehicle to smash into the concrete barrier dividing north- and southbound traffic on the freeway and tip onto its side.

Three lanes of northbound traffic were blocked by the overturned vehicle, and the southbound high-occupancy vehicle lane had to be closed due to a diesel fuel leak from the large rig.

Most of the lanes were reopened about 90 minutes later. The northbound HOV lane was closed for about six hours as crews were forced to offload the truck, which was from Wal-Mart, before setting it upright.

The drivers of both the truck and the car suffered minor injuries, which at first did not appear to require that they be transported to the hospital. But after the semitrailer driver reported starting to feel "queasy" a little while after the accident, he was taken to a local hospital to be checked as a precaution, Robbins said.

Charges in the incident were pending Saturday.