Thirty-one people working in a massive underground tunnel in Los Angeles were rescued Wednesday night after a portion of the structure collapsed, officials said.

A t 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 trapped workers reportedly managed to escape by scrambling over a roughly 12- to 15-foot mound of loose soil to reach four others who had gone in to help.