The California Conservation Corps was found guilty of serious and willful misconduct for failing to follow safety protocols leading up to a fatal van crash that killed four in 2016, the Fresno Bee reports.

A workers’ compensation judge in Fresno ordered the agency to pay an additional 50% in benefits as required by Labor Code Section 4553, based on the finding.

On Feb. 2, 2016, a Conservation Corps van rolled through a stop sign and was hit by a semi travelling at least 50 miles per hour, the Bee reports. The accident killed Ronnie Cruz, 19; Serena Guadarrama, 18; Rhonda Shackelford, 20; and Justin Van Meter, 21.

A California Highway Patrol investigation reportedly found 11 of 15 seat belts in the van were either inoperative or unavailable. Corps members had also complained that van driver Nathan Finnell was driving recklessly.

Judge Geoffrey H. Sims said the California Conservation Corps did not follow its own safety protocols that would have required, among other things, the agency to use another vehicle on the morning of the accident.