The Bensalem gas-station explosion that killed one of its owners and seriously wounded another man Tuesday has been ruled an accident caused by a shop-vac, authorities in the Bucks County township said Thursday.

Joe Vigilante, 63, had been using the vacuum to remove water from a vault constructed 15 feet underground that holds a 12,000-gallon fuel tank when the explosion ripped through the station, according to Rob Sponheimer, a battalion chief with Bensalem fire and rescue. The blast buried him under two feet of rubble.

His body was recovered late Wednesday after a "slow, methodical" search by local firefighters completed without the aid of electronic equipment, out of fear of igniting another explosion.

A woman who answered the door Thursday at the home of Vigilante's brother, Nick, declined to speak with a reporter, saying only that the family had suffered "a tragic loss." The two brothers have co-owned the gas station, on Bristol Pike, for several decades, according to neighbors.

Frank Tomasiello, a part-time worker at the station, was above-ground at the time of the explosion and suffered burns to 45 percent of his body. He remained at Jefferson University Hospital's burn unit in critical condition Thursday.

As investigation of the explosion concluded, state records revealed a history of violations spanning fifteen years at the family-run gas station, including failing to make repairs and maintain required inspection records. The most recent violation was recorded in 2015, and there were no outstanding issues at the time of the blast.

Officials involved in the probe said a mechanical component had been discovered in the vault Thursday, a finding that helped narrow down the cause of the fatal blast.

Vigilante and his brother often used the vacuum to remove accumulated water, maintenance that was done fairly regularly according to Sponheimer

"That's the way they cleaned the water out of the vaults," he said. "That's the way they've done it."

It remained unclear Thursday what conditions were different on the day of the explosion. Sponheimer said the tank had somewhere between 8,500 to 9,000 gallons inside at the time, and that most of the fuel had been recovered after the explosion.

Part of the issue was that the vault is an extremely cramped space, and any combustible vapor that does leak out is difficult to vent, he said. When first responders arrived at the scene Tuesday, the tank showed signs of damage, but it was unclear if it had ruptured before or after the explosion.

Sponheimer noted that none of the alarms at the gas station built to warn about leaks had activated before the explosion.

He was unsure if any of the fuel had leaked into the surrounding vault before the explosion. The state Department of Environmental Protection was continuing its investigation at the scene Thursday to determine if the surrounding area needed to be remediated.

DEP records show that the Vigilantes' station had been cited by the agency for as many as 18 violations since 2003.

Its most recent problems surfaced in 2015 after the station owners failed to conduct a critical 10-year inspection as required. When repeated attempts by the DEP did not prompt the station to inspect the tanks that store gasoline for its pumps, the department sent an inspector who ordered the station to close after finding six violations, records show.

Among the DEP’s concerns in 2015 was that the gas station failed to prevent water from getting inside its underground vault because of decaying manhole covers and unmaintained seals. All three tanks showed signs of deterioration to their outer coating, records show.

Vigilante was told to fix several safety issues and warned by the DEP that more frequent inspections could become necessary.

The DEP followed up that notice with an on-site visit on and were told by Nick Vigilante that an inspection company would begin work the next morning, documents show. When state inspectors returned the following day, they said, no third-party inspector had appeared. Department workers took photographs of the vault and noted water had been pumped from inside and fans were running to dry out the underground area.

The station remained closed for three weeks until its owners cleaned and coated its tanks and took steps to stop water from seeping inside. Vigilante made those repairs, including replacing a manhole cover. The station was allowed to resume pumping gas on July 1, 2015, DEP officials said.

As of Thursday, records show, that was the last time the DEP had concerns about the gas station.