Contractor Charged with Manslaughter after Fatal Trench Collapse

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site of fatal trench collapse in breckenridge colorado 2021
Members of the Red, White & Blue Fire Protection District respond to a fatal trench collapse November 16, 2021, in Breckenridge, Colorado.
Red, White & Blue Fire Protection District

A Colorado contractor has been charged with reckless manslaughter after one of his workers died in a trench collapse in 2021.

Peter Dillon, owner of A4S Construction of Vail, faced penalties of nearly $450,000 in May 2022 by the U.S. Occupational Safety and Health Administration after inspectors determined there was inadequate cave-in protection, among other violations. He contested the violations, and the penalties were reduced to $100,000, according to OSHA online records.

On January 26, 2023, the district attorney for the 5thJudicial District in Colorado announced Dillon had turned himself in on an arrest warrant to the Breckenridge Police Department.

“Business owners and supervisors have a responsibility to properly train and protect their workers from unsafe job conditions which could harm or threaten their lives,” said D.A. Heidi McCollum. “People should not feel like they have to be put in dangerous work situations just to feed their families.”

The fatal cave-in occurred November 16, 2021, when Marlon Alfredo Diaz, 23, was installing a sewer line at a residential construction site overlooking the Breckenridge Ski Resort. Two other workers were also in the trench but were able to escape unharmed.

{Related Content: Trench-Collapse Survivor Tells His Story to Help Others}

Then on December 20, 2021, OSHA inspectors observed a similar violation of workers on the same construction site in a section of a trench that did not have cave-in protection. They reported that trenches had collapsed before on the project.

“Between August and December 2021, the employer routinely assigned workers to work inside trenches that were not protected from cave-ins by an adequate protective system,” according to OSHA’s citation issued May 13, 2022.

“A4S Construction’s failure to comply with excavation requirements cost a worker his life,” said OSHA Area Director Amanda Kupper in Denver at the time of the citation. “Our investigation found that this employer 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.”

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Fire department personnel who responded to the fatal collapse reported seeing a trench box on the site, but it was not in the trench.

Colorado contractor sentenced

This marks the second criminal case for a trench death in Colorado in the past three years.

After a fatal cave-in in 2018 killed 50-year-old Rosario “Chayo” Martínez, who was installing a water line in an 8-foot-deep trench, his employer was sentenced to 10 months in jail in 2021. Bryan D. Johnson, president of residential and commercial general contractor ContractOne of Avon, pleaded guilty to two counts of reckless endangerment and one count of third-degree assault.

Criminal charges filed in trench deaths are not common, typically only a few or less each year.

Willful violations 

In announcing the charges against Dillon, the D.A.’s office cited OSHA reports that the contractor did not have a written safety plan and did not conduct safety audits or inspections at his worksites.

OSHA issued the following violations against A4S on May 13, 2022:

(“Willful violations” are ones in which the employer either knowingly failed to comply or acted with plain indifference to employee safety. “Serious violations” are those when the workplace hazard could cause an accident that would most likely cause death or harm, unless the employer did not know or could not have known of the violation.)

  • Failed to use cave-in protection. Willful violation.
  • Failed to train workers on trench hazards. Willful violation.
  • Failed to provide a safe way for workers to exit the trench. A ladder should be available at least 25 feet from workers, but in this trench, it was 90 feet from workers. Serious violation.

Dillon posted a cash bond of $7,500 and is scheduled to appear in court February 15.