WINDSOR, Colo. — The deaths of two Colorado workers have highlighted one of the most hazardous construction industry accidents.

The Coloradan reports the two men died inside a collapsed trench in Windsor despite a seven-hour effort by 60 first responders at a job site about 17 miles from Fort Collins.

The Occupational Safety and Health Administration last year announced its priority and held a seminar in Colorado to reduce trenching and excavation accidents after 23 workers were killed nationally in 2016, with another 32 in 2017 and 2018.

A Windsor-Severance fire official says it is unclear whether safety devices were in the 15-foot-deep trench.

The official says a metal shelter called a trench box was not present, although it was not immediately apparent if the conditions required one.