MINNEAPOLIS (WCCO) – A Mankato, Minn. man died Saturday afternoon while scuba diving in the Straits of Mackinaw in Michigan, the Cheboygan County Sheriff’s Office said.

Dennis Javens, 64, was died when his tank allegedly ran out of air and he was unable to surface.

According to the Cheboygan County Sheriff’s office, Javens was in Michigan visiting friends when they went diving on the sunken vessel, Cedarville.

Police responded to a call around 1:34 p.m. of an unresponsive male on the shores of Mackinaw City.

Upon arrival, officers and emergency personnel attempted to revive him.

According to police, Javens had a main tank and reserve tank, both of which were in working order.

They believe he made the dive with his reserve tank.

When it ran out of air, thinking it was his main tank, Javens attempted to go get his reserve tank which was empty.

Javens partner noticed he was unresponsive and attempted to get him above water, but couldn’t.

He was eventually retrieved from another group on a separate dive.

Javens was using the body system, which is the sharing of a regulator.

Police said it appeared he was under water for 20 minutes.

The case is still being investigated.