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

The Los Angeles Fire Department rushed to Wilmington after a tunnel collapsed and trapped 27 people inside.Four other workers went in after the collapse to help the others. The construction workers inside the underground tunnel were rescued roughly an hour after the collapse,

Fire officials said the trapped workers managed to escape by scrambling over a roughly 12- to 15-foot mound of loose soil to reach four co-workers who had gone in to help.