A welder killed in a massive explosion at Philips Services Hawaii in Campbell Industrial Park on Oct. 7 accidentally caused the blast that took his life, a Honolulu Fire Department investigation has concluded.

Killed was Sean Miguel Norva, 23, of Waipahu.

"The accident occurred while the worker was welding part of a catwalk that was connected to the top of an oil storage tank," said a fire department media statement released yesterday. "The tank was approximately 15 feet tall and reportedly contained waste oil."

Vapors from the tank were ignited by the welding activities and caused the explosion, the release said. Norva was thrown more than 100 feet from the point of the blast, while the fractured tank was propelled approximately 30 feet.

"The explosion fatally injured the welder," fire investigators concluded, according to the release. "Two other workers who were near the base of the tank when it exploded were seriously injured. A fourth worker at an adjacent business survived the blast with minor injuries."

Preliminary autopsy findings by the Honolulu medical examiner's office listed the cause of Norva's death as multiple internal injuries due to the accident.

Ryan Markham, spokesman for the state Department of Labor and Industrial Relations, said an investigation by the state Occupational, Safety & Health division to determine what procedures had been followed before the explosion has not been completed.

Markham said he did not know when that report would be released to the public.

A police investigation had previously concluded that the explosion was an industrial accident and that nothing criminal was involved.

A Norva family spokesperson said yesterday the family had no comment about the fire investigation findings.

Sean and Kimberly Norva were married Sept. 22. The couple had an 11-month-old son, Khelan James. A fundraiser for the family will be held from 5 to 10 p.m. Sunday at the Pipeline Cafe, 805 Pohukaina St. To donate or for more information, call 479-6004.

A funeral for Norva will be at 6:30 p.m. Oct. 23 at Mililani Mortuary in Waipi'o.