Investigators Still Searching for Clues About Rockwell Deaths : Explosion: Two engineers were killed in incident at the Santa Susana Field Laboratory. Three separate inquiries could take 10 days to several weeks.

As relatives mourned two engineers killed at Rockwell International’s rocket engine test site near Simi Valley, investigators continued searching Wednesday for clues to the cause of the fatal chemical explosion.

Rockwell officials said it could be between 10 days and several weeks before three separate investigations into Tuesday’s blast at the Santa Susana Field Laboratory are completed.

“We have put together what we are confident is the best team of experts available to us,” said Paul Sewell, a spokesman for Rockwell’s Rocketdyne Division. “And we’re going to look at every possibility.”

In addition to Rockwell, the Ventura County Fire Department and the California Division of Occupational Safety and Health are conducting investigations into the accident, the first at the lab involving fatalities since the 1960s.

Rocketdyne engineers Larry A. Pugh, 51, of Thousand Oaks and Otto K. Heiney, 53, of Canoga Park were killed and a third man was seriously injured in the explosion at the 2,700-acre hilltop facility.

The men were preparing for a controlled burn of a catalyst used in solid rocket fuel motors when the accident occurred at 9:07 a.m., officials said. Two unidentified Rockwell workers involved in the outdoor test escaped injury.

“A lot of people lost their friends,” Sewell said, describing the mood of employees at the lab Wednesday, where work went on as usual. “We’re not taking it well.”

Pugh, who had worked for Rockwell since 1977, lived in the Sunset Hills neighborhood of Thousand Oaks for 17 years with his wife, Antoinette, and daughter Meredith, 21.

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Meredith Pugh, a student at Loyola Marymount University, described her father Wednesday as extremely dedicated to his work.

“He absolutely loved his job,” she said. “He had a real passion for science.”

When she was in high school, she said, her father helped her research science projects and experiments.

Although she said she was never “scientifically inclined,” she said that was fine with her father, who had a deep sense of pride about his family.

“He wanted me to just be me,” she said. “He was very proud of our family. We enjoyed spending time together.”

Pugh said her father never mentioned any fears associated with the work he did at Rocketdyne.

“He was never afraid,” she said. “He was very brave.”

A memorial service for Pugh will be held at 7 p.m. today at Pierce Brothers Valley Oaks Memorial Park and Mortuary in Westlake Village.

Heiney’s survivors live in Florida and could not be reached for comment.

Rockwell test mechanic Lee Wells, 62, who suffered second- and third-degree burns over 20% of his body, was listed in stable condition Wednesday. The Newbury Park resident is being treated at the burn center at Sherman Oaks Community Hospital.

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None of the three investigative agencies shed any new light on the possible cause of the accident. Sewell said the men were working on an experiment for Rockwell, not a private contractor.

Cal-OSHA sent two inspectors to Santa Susana immediately following the accident, spokesman Rick Rice said. One inspector will focus on possible worker safety violations, the other on whether criminal activity was associated with the explosion.

“It’s impossible to say at this point how long the investigation is going to take,” Rice said.

If worker safety regulations were violated, a citation would be issued, which could range from a maximum penalty of $7,000 for one violation to several hundred thousand dollars for multiple violations, he said.

Rocketdyne has received six citations since 1990, all for minor health and safety violations, including one $300 fine for failing to keep a proper log of injury accidents, Rice said. Other records of past citations were not immediately available.

The Santa Susana Field Laboratory, which employs 742 workers, is a renowned rocket engine test site for the U.S. Air Force and NASA. The facility has been in operation since 1947, when it was opened by Rocketdyne’s predecessor, North American Aviation.

Rockwell has tested engines for nearly every U.S. rocket program, including the space shuttle and first manned flight to the moon. Current work includes testing of Atlas and Delta rocket engines that propel satellites into space, and the development of hardware for NASA’s space-station project.

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Rockwell officials said Tuesday’s fatalities were not the first at Santa Susana. Six workers were killed in various accidents at the facility in the early 1960s, Sewell said.

“At the time we were testing rocket engines around the clock, seven days a week,” he said. “That’s when we were doing work for the Apollo program. There were 6,000 employees at Santa Susana.”

Here is a look at past fatalities at the lab:

*On Feb. 26, 1963, Rocketdyne electrician Harley C. Rice, 43, of Canoga Park, was electrocuted while inspecting a circuit panel.

*On Nov. 25, 1963, Rocketdyne mechanics Barry D. Hunt, 24, of Woodland Hills, and John M. Scribner, 21, of Reseda, were killed when a storage tank they were cleaning exploded.

*On April 17, 1964, Rocketdyne worker Stanley J. Tykarski, 62, of Canoga Park, was killed when a pressurized tank he was attempting to move exploded.

Sewell said Rockwell officials are certain that there were two other deaths at the lab in the 1960s, but details were not available.

On Wednesday, Joel Jensen, 62, a former Rockwell technician now living in Washington, recalled the 1963 accident involving Hunt and Scribner. He said the two men were flushing out a 30-gallon high-pressure tank when cleaning chemicals reacted with residue in the tank.

“The chemicals got mixed together and it blew up,” he said. “It was kind of like a bomb right in front of them . . . It was kind of sobering to think we were working with stuff that could do that.”

Times staff writer Mary Pols contributed to this story.