One man has serious injuries after a Thursday evening crash involving an off-duty Hennepin County sheriff’s deputy on Interstate 94.

Mark E. Whitsett, 60, of Minnetrista, was heading south on the highway just after 7 p.m. when traffic began to slow near Plymouth Avenue, according to the State Patrol. Whitsett rear-ended the sedan in front of him as the driver, who was an off-duty officer, hit the brakes.

Whitsett was seriously injured during the incident and taken to Hennepin County Medical Center, along with the 47-year-old veteran deputy, Timothy J. Chmielewski. Chmielewski, of Prior Lake, suffered noncritical injuries.