OZAUKEE COUNTY, Wis. (CBS 58) -- The Ozaukee County Sheriff's Office is currently investigating a fatal single-vehicle crash.

It happened around 7 p.m. on Saturday on Mink Ranch Road approximately .5 miles west of CTH KK in Port Washington.

According to the Sheriff's Office, a vehicle was traveling eastbound when it left the roadway, struck a culvert, and rolled several times before coming to rest approximately 200 feet in a farm field.

The driver of the vehicle was ejected and taken to a local hospital by Flight for Life. He later died from his injuries at the hospital.

The driver was identified as 57-year-old Robert Tolson of Port Washington.

A witness reported seeing the vehicle driving erratically prior to the crash.

Alcohol was not a factor, the sheriff's office confirms.

The investigation remains ongoing.