A West Jordan company nicked gas lines six times before excavators snagged a line causing an explosion that leveled a South Salt Lake home in June, killing the elderly woman inside and injuring a passing motorist.

Dorothy Walton, 75, had been talking on the phone to a friend next door when the neighbor heard an explosion and looked out her window to see Walton's house on fire.Even after the woman's death, state investigators believe the Finco Brothers, the West Jordan contractor, damaged service lines three more times, according to a Department of Commerce report. Their report has been turned over to South Salt Lake and the state licensing division for review.

South Salt Lake Mayor Randy Fitts said he's concerned about damage to other lines located where the company crews worked. Following the incident, service lines in areas where the pavement had not been replaced were uncovered and checked for damage. To uncover all the lines would be expensive, he said.

"We're talking a huge expense to look at all of those," Fitts said. Instead, investigators suggested annual leak testing on those pipelines that were not uncovered.

The situation has left a bad taste with city officials.

"I would be very hesitant to use (Finco Brothers) as a subcontractor or any type of contractor," Fitts said.

"We do not put the blame on anybody," said Russell Copeland, manager of the pipeline safety staff of the Division of Public Utilities. "Our report, if you read it, will be quite negative of the contractor and of the operation he did. We think he was quite negligent in certain things."

Finco Brothers was hired as a subcontractor after South Salt Lake approved a street improvement project in 1990. The company was to handle the waterline and storm drainage replacement phases of the project, which stretched from 2100 South to 3300 South on West Temple.

Finco officials could not be reached for comment Friday.

The June 24 explosion came 18 minutes after a Finco employee snagged a 3/4-inch gas line while excavating a trench for a water main, according to investigators. The operator shut off his trackhoe and looked at the pipe but couldn't smell gas or see any breaks.

He called Mountain Fuel to report the snag but was put on hold. The workers, meanwhile, installed the water line that went under the damaged gas line while waiting to report the incident. Unknown to the operator, the snagged service line had disconnected from a coupling under the driveway at Walton's home, 3249 S. West Temple.

When investigators later examined the underground service line, they found the line had separated from the coupling some 12 inches, allowing gas at 60 psi to flow under Walton's yard and into the crawl space under her home, the report says.

It's unknown what exactly sparked the explosion. Walton's son-in-law said he believes it was a furnace or heater.

Mountain Fuel officials maintain they properly marked the excavation site. Their marks were visible after investigators brushed dirt from the area where Finco Brothers were excavating.

Duke Brian, 62, said his mother-in-law died because of negligence and that he intends on suing the responsible party within the month.

"You're darn right they're going to pay for it, somebody is. You bet your boots," Brian said.

"This is a situation that really should have not happened in the first place," said attorney Rick Hinks, who represents Walton's family. "This could have happened to any one of us. No one will accept responsibility."

The circumstances surrounding Walton's death have prompted state pipeline safety investigators to recommend strengthening the existing Blue Stake Law.

They suggest hand-digging in the vicinity of underground utilities and fully exposing them when using power tools.