JACKSON HOLE, Wyo. (AP) — Authorities say dangerous working conditions are to blame for the deaths two men who suffocated in a Wyoming trench.

Teton County Coroner Brent Blue found that Juan Baez-Sanchez and Victoriano Garcia-Perez died last week from compression asphyxiation.

Officials say the trench the Mexican men were digging in the Indian Springs Ranch neighborhood may have collapsed hours before a passer-by noticed an idling piece of heavy equipment and called for help.

Law enforcement found a lack of safety precautions in their initial investigation of the residential construction site in the gated community, and an investigation is now underway by the Occupational Safety and Health Administration.

Authorities say the collapse is not being treated as a crime at this time and no charges have been filed.