LOS ANGELES — All 31 construction workers were rescued without serious injury after a partial collapse inside a large wastewater tunnel under construction in the Wilmington area of Los Angeles, authorities said, bringing a swift end to what officials initially feared could become a prolonged underground rescue.
The collapse occurred on Wednesday evening several miles from the tunnel's only access point, prompting a major emergency response by the Los Angeles Fire Department (LAFD). According to the department, the workers were operating roughly five to six miles inside the tunnel when a section gave way, leaving a large mound of loose soil and debris blocking the passage.
LAFD said the trapped workers managed to climb over an estimated 12- to 15-foot (about 4-meter) pile of debris to reach colleagues on the unaffected side of the tunnel. They were then transported by tunnel vehicles back to the access shaft, where firefighters and paramedics evaluated them.
The department said all 31 workers were brought to the surface alive and had no visible injuries. None required transport to hospitals following on-site medical assessments.
The tunnel is part of the Los Angeles County Sanitation Districts' Clearwater Project, a multiyear infrastructure program intended to modernize the region's wastewater system. Officials said construction work has been suspended while investigators determine what caused the collapse.
Los Angeles County Supervisor Janice Hahn, who visited the site along with Los Angeles Mayor Karen Bass, said the outcome was fortunate given the circumstances.
"We are blessed that all of those men made it out and made it home to their families," Hahn said in a statement, adding that the sanitation district would investigate the cause of the incident and work to prevent a recurrence.
LAFD deployed more than 100 personnel, including urban search-and-rescue teams, hazardous materials specialists, drones and rescue equipment, after initial reports suggested multiple workers were trapped deep underground. Fire officials later said the workers' own efforts to cross the debris significantly aided the successful evacuation.
Authorities have not identified the cause of the collapse, and officials cautioned that the investigation could take time because of the complexity of the underground construction site. The California Division of Occupational Safety and Health (Cal/OSHA) was notified of the workplace incident, according to LAFD.
