At least 31 workers were safely rescued after a tunnel collapsed in a large industrial complex in Los Angeles on Wednesday evening, according to the Los Angeles Fire Department.

       The collapse took place at the "18-foot diameter tunnel, being constructed for municipal wastewater management, occurred at an underground (undetermined depth) horizontal excavation site about 5 to 6 miles south of the sole entry/rescue access portal," LAFD said.

       The trapped workers were able to "scramble with some effort" over a 12-15 foot tall pile of loose soil, to meet several coworkers on the other side of the collapse, and be shuttled several at a time by tunnel vehicle to the entry/access point more than five miles away, according to preliminary reports.

       More than 100 LAFD responders were responding to the scene, including LAFD Urban Search and Rescue team members, "specially trained, certified and equipped to handle confined space tunnel rescue," according to the department.

       Workers were brought out of the tunnel area in a cage hoisted up by a crane; it wasn't immediately clear if that’s the normal way to go in and out of the tunnel project or due to the rescue.

       They came out about eight workers at a time in the cage, and many seemed fine walking out.

       At least 27 of the workers are being evaluated by paramedics at the scene, but all walked out without visible injury, according to the fire department.

       This tunnel is scheduled to be finished by 2027, according to ABC News' affiliate, KABC.

       Los Angeles Mayor Karen Bass arrived at the scene and thanked first responders.

       "I just spoke with many of the workers who were trapped. Thank you to all of our brave first responders who acted immediately. You are L.A.'s true heroes," Bass said on X.