Pasadena Blast Prompts Wider State Safety Inquiry

State investigators probing last week’s electrical vault explosion in Pasadena that killed three city workers said Monday that they are also looking into a similar blast in Los Angeles two years ago, and any other similar explosions, to determine if changes in safety procedures may be required.

Isaac Chae, district manager at the Cal/OSHA office in Covina, said he has contacted other Cal/OSHA offices for reports of vault explosions and has requested that a senior safety engineer with electrical expertise be sent to Pasadena from agency headquarters in San Francisco.

“If it’s occurring all over in a similar nature, we would take a fresh look at it and (devise) safety ordinances,” he said.

“The procedure of how to enter into the vault is one aspect we have to look into,” he added.

It was not immediately clear how many such explosions have occurred or how many Cal/OSHA will include in its investigation. Electrical vault explosions are not uncommon, but power company officials said they do not keep specific figures on such incidents.

Thursday’s blast in Pasadena killed foreman Walter (Glenn) Wise, 50, of Temple City, and two cable splicers, Brian Miles, 36, of Pasadena, and Larry Hokenson, 38, of West Covina.

The men died in a 10-foot-deep underground electrical vault after a 4,000-volt power line exploded about 10:25 p.m. The three had entered the vault to repair a 17,000-volt line that had exploded two hours earlier. Power on the 4,000-volt line had not been disconnected as they worked on the 17,000-volt line.

City officials plan to schedule a memorial service for the three employees later this week. Meanwhile, services for Wise will be held at 10 a.m. today at Rose Hills Memorial Park in Whittier. Services for Miles will be held at 10 a.m. Thursday at the First AME Church in Pasadena.

Information on arrangements for Hokenson was not immediately available.

The Los Angeles explosion occurred July 8, 1988, when a so-called junction box exploded, injuring six of seven workers in a Los Angeles Department of Water and Power vault. A junction box is used to switch power temporarily from one power line to another.

The workers suffered bruises and burns, but all have since returned to work, said Robert McMillen, a Los Angeles water and power engineer.

As in the Pasadena incident, the workers were surrounded by “energized” power lines. Both Pasadena and Los Angeles power department officials said workers avoid shutting down power lines during repairs to avoid cutting off service to customers.

Southern California Edison, which serves 4 million customers, follows a similar procedure, said spokeswoman Diane Wittenberg.

“The technology for working on ‘hot’ lines has been around for decades,” she said. “The chance of random failure of other lines is so remote.”

Wittenberg added, however, that Edison engineers were surprised recently to learn that electrical workers in Britain regularly de-energize power lines while making repairs, leaving customers temporarily without service.