With the threat of a catastrophic explosion looming as a rail car fire raged into its second day Wednesday, Lincoln, California, officials embarked on a risky operation to divert propane from the flaming tanker into a dugout pond, where it could be safely burned off.
The effort, expected to be completed by this morning, was led by a team of professionals from Fort Worth, Texas, flown in by chartered jet late Wednesday for their experience with such emergencies.
"They are nationally recognized as the people to call for this," said Lincoln spokeswoman Jill Thompson.
The procedure - called a "hot tap" - has been used for decades. Perhaps most notably, it was used to help extinguish the Kuwaiti oil well fires in the early 1990s.
But the circumstances in Lincoln - including unbearable heat emanating from the fire and the presence of more propane nearby - made it a uniquely dangerous operation, experts and officials agreed.
As such, about 100 firefighters and paramedics were staged outside the two-mile-wide "blast zone" - covering nearly 5,000 evacuated homes - should anything go awry.
"It's a very dangerous operation, but this is what they do," Daniel Berlant, spokesman for the California Department of Forestry and Fire Protection, said of the Specialized Response Solutions team. "They're really doing a job that's not safe for us (firefighters) to do - and we're trained professionals."
By Wednesday evening - as officials prepared to drill into the tanker to release the propane, arguably the riskiest step in the process - the cause of the fire remained unclear.
About 12:30 p.m. Tuesday, Lincoln Fire Chief Dave Whitt responded to 911 calls about flames shooting from the top of a 30,000-gallon, propane-filled rail car parked on a spur off a Union Pacific mainline. One person had been burned.
Quickly recognizing the gas-fueled blaze would outpace his 24-man department, Whitt summoned help from agencies across the region, including CalFire.
Surveying the area, authorities determined that at least 170,000 - and as many as 500,000 - gallons of propane were captured in nearby rail cars, significantly increasing the risk of an explosion.
Authorities evacuated neighborhoods within a mile radius of the fire, including the downtown commercial core, schools preparing for the first day of classes and the city's signature business, clay-products manufacturer Gladding McBean. Three shelters were opened; nearly 300 residents used them overnight.
Firefighters fought to keep the pressure within the tanker at safe levels, training 5,000 gallons of cooling water a minute at the car through unmanned hoses - the situation was not safe, officials said, for firefighters to be that close.
But as the fire raged on, concerns mounted that the tanker's integrity was deteriorating, increasing the possibility of a deadly blast. Officials feared an outcome like the 1973 Kingman, Ariz., tragedy, in which 11 firefighters died fighting a propane explosion at a railyard there.
Though officials said the SRS's "hot tap" operation was the best solution possible, their hesitation was clear: Twice during a morning press conference, Whitt said he was "fairly confident" the effort would work. Later, Berlant of CalFire was clear that the potential for disaster remained.
"It's a very high-intensity task," he said.
According to experts, the "hot tap" process is used frequently as a way to safely tap into a pressurized pipeline or vessel that can't be depressurized or cut off. For example, a "hot tap" can be used to create a pipeline for a new residential neighborhood off a city's natural gas mainline, said Kyle Makofka, vice president of business development for the Canadian firm Red Flame Industries.
He said his company does roughly 1,500 "hot taps" annually, most with little danger.
However, he said the situation in Lincoln is "substantially different," in part because the fire is creating its own pressure and temperature challenges.
"Now you have external risk starting to affect the job," Makofka said.
He added that the presence of highly flammable propane increases the risk of a blast: "You don't want to be in the area when that happens."
Others observing the blaze - including the company that owns the burning propane and the property - appeared to share that concern. "We are 30 hours into this release. It is of great concern to us," said Eric Beatty, secretary and general counsel of Heritage Propane, which uses the name Northern Energy at some of its propane storage facilities, including this one.
A Heritage Propane crew was preparing to unload the propane - produced by British Petroleum - from the rail car into its facility when the fire ignited.
The facility is a terminal where propane gas, brought in by rail, is stored in bulk tanks before being trucked to retail outlets.
Hazmat crews from UP and the Federal Railroad Administration were on scene to assist firefighters. The California Public Utilities Commission, which conducts hazmat inspections, also had representatives on scene to conduct an investigation.
In an email to The Bee, the PUC said an "early review of inspection reports reveal good practices on the part of the shipper, Heritage, but we will perform a more thorough review of Heritage's records."
The PUC said Heritage Propane employees also have received federally required training on safe handling of hazardous materials while loading and unloading, and participated this year in a federal seminar on federal hazmat handling regulations.
On Wednesday evening, residents waited anxiously for updates. At one shelter, volunteers tried to keep spirits up with a barbecue and free ice cream. Representatives from insurance companies were on hand to counsel evacuees - and give out free dog food.
"We're just ... getting as much information as we can, talking with friends, just waiting it out," said Linda Kaveney, who was there with her twin sister and 18-year-old daughter.
Earlier, officials had forewarned residents that a huge, dark plume of smoke would develop that evening, once the dugout pond was filled with burning propane. But even as the propane's flammability posed a threat to firefighters, it didn't pose one to the ozone.
"Propane in its nature is a clean-burning fuel ... and there are no toxins associated with (its) combustion," said Heather Kuklo, of the Placer County Air Pollution Control District.
"That, in and of itself, is a real positive for this situation."