DENVER (AP) -- The Denver Office of the Medical Examiner has ruled the death of a Minnesota native whose body was found nearly a month after he disappeared as an accident.

Twenty-nine-year-old Adam Gilbertson, a registered nurse, never showed up to work on Dec. 15 after a night out in Denver.

Gilbertson's family organized a search party and his body was found Jan. 13 along the South Platte River.

The autopsy report says Gilbertson died as a result of the combined effects of alcohol, hydrocodone and amphetamine ``in combination with possible fresh water drowning.''