A Vail, Colo.-based contractor faces nearly $450,000 in federal penalties for a November 2021 trench collapse that fatally injured one worker and nearly cost the lives of two others.

A U.S. Occupational Safety and Health Administration investigation determined that A4S LLC, operating as A4S Construction, knowingly failed to install a trench protection system for the sewer line project, located in a Breckenridge, Colo., neighborhood, when the trench wall gave way on Nov. 16. One worker, identified as 20-year-old Marlon Diaz, died as a result of blunt force trauma injuries suffered during the collapse, while two others were rescued.

OSHA investigators also found that while the Breckenridge project had experienced other trench collapses prior to the fatal incident, A4S allegedly failed to change its practices. In a statement, OSHA Area Director Amanda Kupper said that A4S “willfully sent workers into unprotected trenches at a site with a history of cave-ins, and continued to expose workers to the same conditions even after the fatality.”

The investigation resulted in three willful citations for not ensuring the excavation was inspected by a competent person, failing to perform an inspection of the excavation and not having a trench protective system in place. A4S Construction was also issued an additional serious citation for not having a safe means of egress within 25 lateral feet of employees working in a trench.

In addition to proposed penalties of $449,583, OSHA has placed A4S Construction in its Severe Violator Enforcement Program, which focuses enforcement efforts on employers who willfully and repeatedly endanger workers by exposing them to serious hazards. The enforcement measures will include mandatory follow-up inspections of the Breckenridge jobsite, as well as inspections of other A4S projects of where similar hazards or deficiencies may be present.

A4S did not respond to a request for comment.

According to OSHA, the company has 15 business days from receipt of the citations and penalties to comply, request an informal conference with the agency’s area director or contest the findings before the independent Occupational Safety and Health Review Commission.