MENLO PARK (KCBS) – Investigators from the California Division of Occupational Safety and Health will be back in Menlo Park on Tuesday searching for clues as to exactly what caused an explosion at Membrane Technology and Research last week.

The explosion last Friday killed 56-year-old engineer Adrian Martin. Menlo Park Fire Protection District Chief Harold Schapelhouman said Martin was transferring a mixture of methane, helium and nitrogen from one cylinder to another when the blast occurred.

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KCBS’ Betsy Gebhart Reports:

“The goal will be to try to find exactly what that was and what caused the explosion,” Schapelhouman said. “Was it an overpressure, a rupture or a failure of some sort?”

Fire officials said that the research and development laboratory had passed a safety inspection as recently as March.

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Cal-OSHA investigators worked into the early morning hours on Saturday gathering evidence. Menlo Park fire officials are expected to go through the company’s case file to see if there were any other past issues at the facility.

Twenty-five people were evacuated from the two-story building. One other employee, Jenny He, was slightly injured in the blast but released from Stanford Medical Center Friday night.

Membrane Technology and Research’s President, Hans Wijmans, issued a statement over the weekend and said he couldn’t comment on the cause of the explosion because of the ongoing investigation.  He also expressed his condolences to Martin’s wife, daughter and other family members.

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