Thirty-one construction workers escaped harm Wednesday night after part of the Clearwater Tunneling Project in Wilmington, California, collapsed underground.

More than 100 Los Angeles firefighters — including specialized urban search and rescue crews — responded near Figueroa Street and Lomita Boulevard around 8 p.m. Within about an hour, all trapped workers were brought out safely.

“All missing persons were removed,” confirmed Brian Humphrey, spokesperson for the Los Angeles Fire Department.

The 18-foot-diameter tunnel is part of a $630 million effort to move wastewater from Carson to San Pedro. It collapsed about five to six miles south of its only access point, according to Humphrey. Some trapped workers pushed through loose soil up to 15 feet high to reach co-workers and escape. TV footage showed workers lifted out by crane in a rescue cage.

Family members waited anxiously nearby. Maria Orozco, who has three sons working on the tunnel, rushed to the scene.

“I’m waiting for my sons,” she said in Spanish. “I need to know for sure if they’re safe, I have three sons working here and they’re not answering their phones.”

She later explained, “I was at church and today it was my daughter’s turn to pray and I asked her to pray for my sons… I really felt it in my heart that something happened.”

Relief came when one of her sons called to say they were safe.

“They have their own children as well who were worried,” Orozco said. “I want to see them, I want to see them.”

Interim Fire Chief Ronnie Villanueva reassured her: “Don’t worry. I saw all of them and it looks like they’re all fine.”

Workers were trapped for about an hour, with water reaching up to their mid-thighs. OSHA will investigate the incident, as is standard for workplace accidents.

Michael Chee, spokesperson for the Los Angeles County Sanitation Districts, said: “What I just got a report on is that 31 crew members were down in the tunnel. They have all been extricated safely. There are no significant or major injuries that I know of.”

Mayor Karen Bass spoke with rescued workers who were already calling loved ones.

The contractor, Dragados USA Inc., specializes in tunnel-boring and began this $630 million project to replace aging pipes installed in 1937 and 1958. The tunnel, approved in 2021, was planned for completion in three to four years — but the collapse will likely cause delays.

Large-scale tunneling projects like Clearwater are critical to modernize aging infrastructure in urban areas like Los Angeles County, where wastewater systems date back nearly a century.

The collapse highlights the high-risk environment of underground construction and the crucial role of specialized urban rescue teams in responding quickly. It also underscores the importance of rigorous safety oversight, with OSHA now investigating the cause.

Officials say this incident could prompt closer scrutiny of tunneling safety protocols and emergency access planning for other large civil projects statewide.

Despite the scare, the outcome — all 31 workers rescued with no visible injuries — stands as a testament to training, teamwork, and the quick actions of rescue crews and workers alike.

Originally reported by Construction Equipment.