An explosion may have caused Wednesday's fatal water tank accident in Oildale, state investigators theorized Thursday.

A Cal-OSHA spokesman said the two men involved in the accident were using water and highly pressurized air to check for leaks in the tank. Something may have caused the pressure to release suddenly, vaulting the workers into the air, he said.

"The pressure could have built upwards, which would, you know, propel them. So it may not have been that they fell as much as they were hurled. But we don't know that," agency spokesman Peter Melton said, adding that Cal-OSHA's investigation will take months.

Authorities said Barry Snelson, a 54-year-old welder, was killed in the accident after apparently hitting his head during a fall inside the tank, located at an oil field power plant and steam generation facility. An unidentified supervisor inside the tank with Snelson suffered a broken ankle.

Both men were working for Brahma Group Inc., a Salt Lake City-based engineering and contracting firm. Messages left with Brahma representatives in Bakersfield and Utah went unanswered Wednesday and Thursday.

Cal-OSHA's comments Thursday presented a new picture of what may have triggered the accident. The agency and the Kern County Fire Department originally suggested that a "false floor" the men were standing on gave way at about 9:30 a.m.

But Melton noted that the false floor -- a permanent feature of the structure rather than the temporary modification authorities described Wednesday -- was only six inches to a foot above the bottom of the tank.

Melton emphasized that investigators have much work ahead of them, and that they had not yet reviewed Brahma's safety plan.

Snelson's oldest daughter, Nicole Rivers, said Brahma's chief executive officer flew out to meet the family Thursday and offered to cover funeral costs.

She said her father was a wonderful son, brother, husband, father of three and grandfather of three.

"He would give the shirt off his back to anyone that needed it," she said. "There was not a person that didn't like him. He was very humorous and kind-hearted."

Arrangements have been made with Greenlawn Mortuary & Cemetery for a viewing from 4 to 7 p.m. Wednesday at Greenlawn Memorial Chapel, followed by a funeral service at 10 a.m. Thursday.