A highway overpass that had been judged safe by state inspectors collapsed Thursday morning when a semitrailer truck traveling east on I-84 hit the column supporting the structure.

One person was killed.Idaho State Police Cpl. Steve Hobbs, the investigating officer, said the accident occurred about 4:15 a.m. four miles east of Burley, Idaho, in Minidoka County.

The driver of the truck apparently fell asleep at the wheel, Hobbs said. The truck crossed the grassy median and struck the concrete column of the overpass on the westbound lane. One hundred tons of concrete fell some 15 to 20 feet.

The lone occupant of the truck, Harliss Coleman, no age available, Austin, Texas, was declared dead at the scene. He was driving a Sheerwood Co. truck filled with house-hold goods to military installations.

Asked if the overpass was unsound, Hobbs said authorities were unaware it was unsafe. "We had no idea it would come down like that, but we don't do stress tests with semitrucks hitting the columns. It was a freak thing."

At 11 a.m., the body of the victim was still not recovered. The officer said it's too grave a risk to emergency personnel to pull him out until the area is stabilized.

All traffic on the westbound lane of the freeway was detoured through Burley and onto alternate highways. The eastbound lane was moving slowly.

Officers expected to have the westbound lanes open later Thursday night.

Witness Ken Moore of Spruce Crow, Alberta, Canada, said he was driving west and talking on a citizen-band radio when he saw the Coleman truck heading straight for him.

He said the truck crossed the median and he hollered into the CB, "He's coming right at us!" A third truck slammed on its brakes, throwing one of the relief drivers out of the bunk behind the driver. That truck managed to stop before the bridge collapsed.

Moore continued on and his truck was hit by the falling overpass as he went under the collapsing bridge. It tore the roof from the trailer and off the driver's side. It also dropped 100 bales of peat moss over the freeway.

"A half a heartbeat earlier and I would have been under it," Moore said. "It's too close for comfort." He was visibly shaken but not injured.

"I'm going to church for sure now," he said.

Police were able to alert authorities immediately as a result of Moore's CB transmission.

The bridge over the westbound lane of I-84 is completely collapsed. One section of the highway is in about a 45-degree position and the other half is lying on the truck.

Concrete debris from the overpass columns are lying about in giant chunks. The road surface is on the ground in sections. A great deal of debris is lying about the freeway, and Coleman's truck is so badly crushed it's almost unrecognizable.

Doug Chase, bridge maintenance engineer for the Idaho Department of Transportation, said the bridge that collapsed was actually considered to be one of the better bridges in the state before the truck collided with it. "It was in good shape."

State and federal reports had given it a "sufficiency" rating of 84.8 on a scale of 0 to 100. Federal guidelines say that bridges with ratings lower than 80 are in need of renovation - so the condition of the collapsed bridge was nearing that threshold.

Coincidentally, a copyrighted story in the Deseret News on Wednesday examined the condition of such road bridges within Utah.

That story reported that one of every 13 bridges in the Utah is classified "deficient." Federal records show that in comparison, one of every three bridges in Idaho is deficient - but, of course, that did not include the collapsed bridge.

A "deficient" rating does not mean a bridge is necessarily structurally unsafe, although many are. It may mean it is too narrow, not designed for present loads or needs prompt repairs - although it may not be expected to fail immediately.

Still, reports by Utah bridge inspectors show that two-thirds of the 332 deficient Utah bridges have serious structural problems.

Utah has 332 of its 2,463 bridges classified as deficient. Idaho has 1,087 deficient bridges out of a total of 3,716, federal records show.

Chase said that he and a design engineer planned to visit the collapsed bridge Thursday. "We need to determine whether we will rebuild the present structure or completely replace it."