Cass County Sheriff Joe Underwood Jr. said a 48-year-old Three Rivers man died over the weekend in a one-vehicle accident in Marcellus Township.
The incident occurred about 7 a.m. Saturday on Burlington Road, south of Marcellus Highway.
Underwood said a Chevy Impala driven by John Eastes left the roadway, struck a tree and came to rest in a swampy area.
Easts was transported to Bronson Methodist Hospital via AirCare and was listed in critical condition.
A passenger in the vehicle, Robert Haney, 47, from New Mexico, was killed in the crash. It is unknown if alcohol was a factor in the incident.