One person has died and three others hospitalized after being found unconscious in a camp trailer in Delta, Colo., Saturday evening (Jan. 1), the Delta Police Department said.

Jamie Head, spokeswoman for the Delta Police Department, identified the dead man as Jack Herrera, 50, of Delta, The Denver Post reported.

The cause of death was acute carbon monoxide poisoning.

The death was ruled accidental by the Delta County Coroner’s Office, said Head.

Officers were sent to 1675 Highway 92 — Valley Sunset RV Park — about 7:30 p.m. Saturday after police were alerted to the situation, according to Head.

Two women and one man were taken to Delta County Memorial Hospital. The fourth person, Herrera, was pronounced dead at the scene.

Head said it was not immediately clear what in the trailer emitted the carbon monoxide and the investigation is continuing, Head said.

The manager of the park, who asked to be identified only as Teresa, said the victims were discovered when a friend of the trailer owner — who survived — found the four persons unconscious.

Two of the people taken to the hospital have been released; the third is expected to be released today, said Head.

The man who owned the trailer has been living at the 11-acre facility for about two months, the manager said, adding that the man who died was also from Delta.