A giant overpass being built over one of California's busiest freeways has caught fire and collapsed completely, necessitating the demolition of the entire project.

According to the San Bernandino County Fire Department’s Twitter account, the blaze was caused by construction workers who were using blowtorches to cut through the reinforcing bars of the bridge, which passes over the busy 15 Freeway linking Los Angeles and Las Vegas. The blowtorches accidentally set fire to the timber…