Explosions Touched Off by Gasoline in Sewers

A mysterious and dangerous gasoline leak into sewers in the San Fernando Valley forced more than 200 residents temporarily from their homes Saturday. The leak produced highly flammable vapors that caused several minor explosions and forced dozens of firefighters into a daylong battle to try to dilute the fumes.

No injuries resulted from the explosions, and only minor damage was reported in three homes when flames erupted near sewer lines, officials said.

However, a Los Angeles Fire Department spokesman characterized the fumes as highly explosive, reaching 100% flammability levels in some places.

“It’s the worst possible situation that you can get for the gas vapors being in the air at a maximum level,” said city Fire Department Inspector Ed Reed. “It’s very flammable.”

Residents Detect Fumes

Reed estimated that about 300 to 400 gallons of gasoline had seeped into sewer lines from an unidentified source, resulting in fumes residents could detect from toilets, manhole covers and other sewer vents.

Although officials believed the problem was under control by mid-afternoon, fumes reappeared “at high readings” about 6:30 p.m.

Fire officials believed the leak might have come from an underground high-pressure gasoline line in a Mission Hills neighborhood near Arleta Avenue and Ducat Street, said Assistant Los Angeles Fire Chief Alfred Vega.

Officials were also checking for underground spills from several gas stations located along the sewer lines. Los Angeles County health officials also plan to investigate, said city Fire Department spokesman Jim Wells.

More than 100 homes in an area of Mission Hills partly bordered by the Golden State Freeway and the Simi Valley Freeway were without power, and residents were asked to stay outside their homes for most of the day and evening.

Fire Department officials feared the gas might ignite and possibly explode around homes as it made its way through the 30-mile sewer system to the Hyperion Sewage Treatment Plant in El Segundo.

From the northeast Valley into Los Angeles, firefighters lifted manholes and pumped a light foam into sewers to contain the vapors and dilute the gas as it flowed toward the Hyperion plant, Vega said.

Other Cities Alerted

In addition, Hyperion officials alerted city treatment plants in Glendale and Van Nuys to watch for gasoline-tainted sewage, said Dave Gumaer, a shift supervisor at Hyperion.

Vega said the first hint of trouble came around 9:30 a.m. when several people reported smelling gas in their bathrooms on Arleta Street.

“I smelled gas coming from the toilet and in the back of the house,” said Guillermo Iturbe, 23. “Then I saw this woman across the street screaming in Spanish that there was a fire behind her house.”

Vega said there were four small “very minor” explosions around the neighborhood before natural gas valves could be shut off. Small fires in three of those instances caused $1,200 in damage, Wells said.

Very High Readings

“The readings were very high, and that really worried us, because the chances of explosions were very high,” Vega said of flammability levels recorded at 100% in some areas as late as 8:30 p.m.

Despite the potential for danger, residents remained largely calm, and complained about the inconvenience. Many ignored the warnings and stayed inside their homes.

Julie Nelson, 18, said she stayed at her Ducat Street home with the power shut off and the windows open.

“I can’t curl my hair, so I’m not going anywhere,” Nelson said. “My garage smells like a gas station . . . I won’t smoke a cigarette for a couple of days.”