None of the 31 construction workers rescued in the tunnel sustained visible injuries, according to LAFD. Firefighters said construction workers climbed over a roughly 12 to 15-foot pile of dirt to escape.

A massive tunnel under construction partially collapsed in Los Angeles County, trapping 31 workers 400 feet beneath the ground. All the workers were safely rescued.

Some days, even the most carefully planned subterranean construction is ruined by an unexpected, thunderous collapse an incident that puts first responders to the test and challenges the resilience of contemporary tunnel construction and safety standards.