Tunnel Collapse: How 31 Workers Escaped Death Through Miles Of Darkness Hundreds Of Feet Down

WILMINGTON, CA — Arally Orozco was at church Wednesday evening when she was notified that her three brothers were stuck after a tunnel collapsed at their job site in Wilmington.

She began fearing the worst. Meanwhile, 400 feet underground, her three brothers and a dozen other workers scrambled to find a way out. Water began to rush through with such force that it pulled at the transported vehicle they used to get around in the tunnel.

Her brother started feeling like he couldn't breathe. As if the tunnel was losing oxygen, Orozco said her brother told her.

"They felt helpless," Orozco said. "He told me he thought he was going to die underground."

It's unclear exactly what caused the tunnel to cave in.

Workers heard a hissing sound

Michael Chee, spokesperson for the Los Angeles County Sanitation Districts, said the tunnel is part of a multi-million-dollar project that began two years ago.

It's meant to transport water treated at the nearby wastewater treatment plant directly to the ocean near San Pedro. Right now, two different pipes move the water underground, but they are decades old, Chee said.

The new tunnel, which is 18 feet wide and seven miles long, was at the last stretch of its completion when the collapse happened.

"The collapse happened at about the five-mile marker," Chee told Patch. "Unfortunately, although none of them were harmed and none of them were seriously injured, they did have to make their way out by foot or by limited transport for the rest of the five miles."

Chee said the overall sentiment amongst the workers was that they were fortunate to be alive.

"But they were traumatized, obviously, by the experience," Chee said. "...shaken by the experience as anyone would be."

Tunnel operations have been shut down for safety reasons and the digging machine remains underground. Chee said nobody has been able to reach the site of the collapse and there is no time frame as to when someone will be able to inspect the area.

It took workers nearly an hour to get to the five-mile marker. Chee said they were there to supervise the boring machine, which digs out the corridor and builds the tunnel at the same time.

Once there, according to Orozco, workers heard a hissing sound.

"They heard like a psss sound, like air was going out, like pressure was escaping, and they didn’t know what it was,” Orozco said.

Later, as some workers made their way back through the tunnel, debris started falling down, Orozco's brothers told her.

Afraid of being trapped down there, they climbed a large pile of debris left behind by the collapse, meeting their coworkers on the other side.

After getting through the most perilous part of themselves, they began the miles-long journey back to the only entry point at 1701 N. Figueroa St.

They made it home to their families

One of Orozco's brothers came out of the tunnel crying.

The Los Angeles Fire Department said 31 workers were safely removed from the tunnel with no visible injuries.

City Councilmember Tim McOsker, who represents the Harbor region, praised the workers for keeping calm throughout the emergency.

“This is a highly technical, difficult project. And they knew exactly what to do. They knew how to secure themselves,” he said. “Thank goodness for the good people that were down in the tunnel.”

Mayor Karen Bass said at a news conference that she met with some of the workers.

“I know when we raced down here I was so concerned that we were going to find tragedy. Instead, what we found was victory," Bass said.

Los Angeles County Supervisor Janice Hahn, who is also on a county sanitation district board, said the district would be looking into what caused the tunnel to cave in and try to ensure it doesn't happen again in the future.

"We are blessed that all of the men who were trapped made it out and made it home to their families," Hahn said in a statement on social media Thursday. "Most people in the Harbor Area communities didn’t even realize that this tunnel was being bored beneath them, but these men go to work every night to build this critical infrastructure project for our region."

Digging underground

The project has been underway for two years without any problems, Chee said.

“The tunnel boring machine has been digging under streets, public right-of-ways, homes, parks, lakes, ponds, golf courses without incident until now,” he said.

Officials will investigate to determine the cause, Chee said.

“What our people and what our contractors and their specialists are going to do is a full assessment," he said. “Everything from the engineering to the structural integrity to the safety, and obviously a very close inspection and look at the actual collapse point in the tunnel before anything else is done.”

Working so near the shoreline and at such a depth means crews could have been contending with very wet conditions that add challenges during design and digging, said Maria Mohammed, president of the Structural Engineers Association of Southern California.

“You would design not just for the pressure from the soil and the weight of the soil, you have to design for the pressure from the water,” said Mohammed, whose group is not involved in the Wilmington project.

Mohammed said the investigation could take months, if not longer. It will take some time just to make the tunnel safe for investigators to enter. Once inside, they'll try to determine where the collapse originated, she said.

“It all comes down to, what’s the first element that broke?” Mohammed said. “Usually a collapse is a propagating thing. One thing fails and it takes other things with it. So you would try to figure out, of the broken elements, which one broke first.”

AP News contributed to this report.