An underground pipeline has spewed out thousands of gallons of crude oil near the Southern Californian coast.
The oil was contained in a lengthy stretch of ravine before it could reach nearby beaches.
About 29,000 gallons of oil was spilled, flowing at least a quarter-mile in the canyon near Ventura.
Resident Kirk Atwater said he called 911 after smelling and hearing the flowing crude.
“We started getting this horrendous smell and I knew right away what it was,” he said.
Mr Atwater, 56, went up the canyon on his motor scooter and found the oil gushing from an above-ground box.
“It was just pouring out like water coming out of a fire hydrant,” he said.
Fire crews responded to emergency calls and a pump house operating the line was shut down. Firefighters then built a dam of dirt to keep the oil from moving further.
The line operator, Crimson Pipeline, estimated that at most 25,200 gallons were released, said spokeswoman Kendall Klingler. The cause is under investigation.
The spill was the 11th for Crimson since 2006, with prior releases totalling 313,000 gallons of crude and causing 5.9 million dollars (£4 million) in property damage, according to accident
The largest was a 2008 spill of 280,000 gallons – one of three blamed on equipment failure. All the spills occurred in Southern California.
Thursday’s leak occurred near a valve on an underground line that runs from Ventura to Los Angeles. The line was closed for maintenance and crews had replaced that valve the day before, Mr
The line contained a total of 84,000 gallons of crude.
“The initial concern was that there was a chance that it could have made its way further, but the spill was contained very early on and a lot of damage has been mitigated because of that,” Mr Klingler said.
The spill occurred in the Hall Canyon area and flowed into the Prince Barranca, a ravine that ends near the Ventura Pier. Initial projections that up to 210,000 gallons may have spilled were later reduced.
The oil was produced by a company called Aera Energy.
Firefighters took part in a training exercise with Crimson and an oil spill clean-up company about two weeks ago, including building a dam such as they constructed on Thursday, Ventura County fire captain Scott Quirarte said.
Four of the prior Crimson spills were blamed on corrosion and two on excavation damage. An electrical arc from a power pole was identified as the cause of another leak.
Mr Klinger defended the company’s safety record and said most of the past spills were caused by third parties.
The company said its California network traverses about 1,000 miles and moves nearly 200,000 barrels – 8.4 million gallons – of oil daily.
The spill came 13 months after more than 120,000 gallons of oil spilled on the coast of neighbouring Santa Barbara County. Some of the crude flowed into the ocean at Refugio State Beach and killed birds and sea lions.
That pipeline, owned by Plains All American Pipeline, was found to have corrosion.
Federal regulators said last month that Plains failed to prevent corrosion in its pipes, detect the rupture or respond swiftly as crude streamed toward the ocean on May 19 2015.
The report was issued just two days after Plains was indicted in Santa Barbara County Superior Court on 46 criminal counts, including four felonies of polluting state waters and three dozen misdemeanours of harming wildlife.