Update, 1:30 p.m. Saturday 

On Saturday afternoon, the fire was still burning and the employee was still unaccounted for, said Tristan Babin, a spokesman for St. Charles Parish.

Original story

A natural gas pipeline in St. Charles Parish that erupted in flames Thursday night was still ablaze almost a full day later, with one worker missing and another recuperating in a hospital burn unit.

Officials and plant workers could do little Friday but seal off the section of pipe that caught fire and wait for the gas inside to burn off. Authorities warned it could be hours or days more before the flames were entirely extinguished, although the fire had shrunk considerably by early evening.

Those evacuated from homes in the small community of Paradis, where the fire started, were allowed back home about midday Friday, though some remained wary of returning before the fire had been put out.

“We are going to wait a little while because the kids — I don’t think they’re ready to go back yet,” said Earlyandra Robinson, 32, who lives two blocks from the site of the fire and sought shelter at a community center in Luling. “We don’t want to take any chances.”

Robinson described hearing a series of thunderous booms Thursday evening. She said it sounded like food being boiled, only “10 times louder.” Then her son pointed out the enormous cloud enveloping the neighborhood.

Todd Denton, general manager of midstream operations for Phillips 66, the company that owns the pipeline, said Friday it was the most serious industrial accident of his career. “I can’t express strongly enough the concern I have and that the Phillips 66 family has for those impacted,” he said.

The missing worker and those who were injured have yet to be identified by company officials. One worker received treatment at a nearby hospital and was released, while another was listed in fair condition after being airlifted to the regional burn unit at Baton Rouge General Hospital.

Other workers were evaluated on the scene and released.

The fire began in a fenced-off, 800-square-foot area around which six workers — three employed by Phillips 66 and three by Blanchard Contractors — were trying to clean out a section of the pipeline, officials said.

Oil and gas companies routinely send pieces of equipment called “pigs” down the line. They look like sea urchins and are supposed to clear debris from the inside of a pipe, either for regular maintenance or to clear the way for other equipment used to check for leaks or corrosion, said Tyler Gray, general counsel for the Louisiana Mid-Continent Oil and Gas Association.

To launch a pig, crews typically burn off the fuel in the pipe, then seal off the section so it can be depressurized. Then they load the pig, seal the pipe back up and open the valve, allowing the liquefied natural gas to push the equipment through.

“We were receiving that pig,” Denton said. “We don’t know what happened after that.”

Between depressurizing and pressurizing the pipeline and burning off gas, running the equipment can be dangerous, experts said, especially if all the gas doesn’t burn off or if there’s a leak in the line or some other problem.

Steven Giambrone, director of the state Department of Natural Resources’ pipeline safety program, said it’s too early to speculate on the precise cause of Thursday's fire. His office has 30 days to prepare an investigative report.

The federal Occupational Safety and Health Administration also has begun a probe, said Steve Barr, a U.S. Department of Labor spokesman.

The pipeline, built in 1958, runs 86.6 miles between Venice and Paradis. Thursday marked the second time it ignited since 2013. The first time it caught fire was after it was struck by a boat in a bayou where Jefferson and Lafourche parishes meet. 

Its operators haven’t incurred any violation notices since at least 2008, when the DNR began filing its records electronically, Giambrone said.

Chevron, which sold the pipeline recently to Phillips 66, was given notice to perform better surveys in the area in 2015, but that issue has been resolved and had “nothing to do” with the fire, Giambrone added.

According to online records, Phillips 66 has received four corrective action orders since 2002 from the U.S. Department of Transportation, which oversees interstate pipelines. None of the incidents were in Louisiana.

There are various levels of notices and warnings, but orders are for more serious pipeline incidents, such as Phillips' most recent case, when 700 barrels of crude oil spilled near Plains, Texas, in 2008.

Still, environmental groups seized on the fire as an example of the dangers posed by pipelines carrying fossil fuels. Those groups hope to halt the construction of another line, the Bayou Bridge Pipeline, in which Phillips 66 is a partner.

Conservationists are planning to rally outside the state Department of Environmental Quality at 10:30 a.m. Monday to keep up the opposition.

“As the Phillips 66 pipeline fire continues to burn, can we really trust their assurances that another pipeline would be safe?” Cyn Sarthou, executive director of the Gulf Restoration Network, asked in a statement. “Clearly, if the Bayou Bridge pipeline is built, it will place our communities and our workers at risk.”

Regulators argued that the comparison doesn’t hold water. The Venice-Paradis line that caught fire Thursday transports liquid natural gas, while Bayou Bridge would carry crude oil.

Venice-Paradis is really like Bayou Bridge only "in the sense that it is a pipeline," said Department of Natural Resources communications director Patrick Courreges.

"In terms of the regulatory community, (the fire) doesn't have any bearing on” the Bayou Bridge debate, said DEQ spokesman Greg Langley.

There are risks associated with pipelines, but trains and other methods of transportation have potential dangers as well, Langley said. "Any method you use has some risk. ... The alternative is don't use any oil," he said.

Anne Rolfes, director of the Louisiana Bucket Brigade, an environmental group, was unconvinced.

Industrialists and politicians friendly to them may offer excuses and claim that new technology will make future lines safer, she said in a statement. “But the fire and the explosion speak for itself. Pipelines are dangerous, and we don't want more in Louisiana."

One of the major concerns about Bayou Bridge is that crude oil will leak into rivers, contaminating wetlands and drinking water. Natural gas is much more volatile; St. Charles Parish Sheriff Greg Champagne described the scene in Paradis as “a large blowtorch.”

Despite the plume of black smoke that still hung over the pipeline Friday afternoon, company and local authorities repeatedly said that all available data indicated there were no “health impacts to the surrounding community” as a result of the fire. 

Follow Steve Hardy on Twitter, @SteveRHardy.