The driver of a truck hauling a mobile home lost his load Saturday and watched helplessly as it sheared a main Utah Power & Light Co. tower in half, leaving thousands of South Davis County residents without power.

"He was pretty shaken up; there wasn't much he could do after the trailer came unhitched," Utah Highway Patrol trooper Stan Olsen said.Cars jammed northbound and southbound lanes of I-15 near Lagoon for almost an hour while crews from Farmington Fire Department lifted the 47,000 volt line from the highway. The line draped across all four lanes and backed traffic for three miles in both directions.

The truck was southbound entering I-15 from the U-89 onramp when it hit a bump and the trailer holding one-half of a double-wide mobile home came unhitched and broke its safety chain.

"It just started bouncing. The driver lost control and his load slammed into the pole," Olsen said.

Union Pacific trains also were delayed for two hours while UP&L workers lifted the line and several other auxiliary lines from the tracks next to I-15.

The accident knocked out power at 8:55 a.m. to most of Kaysville, Farmington, Fruit Heights and parts of Layton. Power was restored to the area about noon.

UP&L crews worked all day Saturday toreplace the 75-foot wooden tower, which held the main line servicing South Davis County, spokesman John Serfustini said.

Meanwhile, power was switched from other substations and transformers to restore electricity.

Four cars were damaged slightly from the falling wire, but no injuries were reported, Olsen said.

"Things were crazy here for a while; we had parts of this high-voltage power line eight feet off the ground and high-profile trucks coming," he said. "We arrived and sparks were flying everywhere."

Several cars passed over the fallen line before emergency personnel arrived, and one car stopped with the wire draped over its trunk, Farmington Fire Chief Dave White said.

Police officers from Centerville, Kaysville, Farmington and UHP had their hands full managing hundreds of people who stopped to look at the accident.

"We had to yell at a few people to get back from the wires, but maybe it saved their lives," Olsen said.