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.

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.

Los Angeles Fire Department Capt. Danny Wu explained the efforts by first responders to rescue at least 31 workers after a tunnel collapse in the city.