PORTAGE, Ind. (STMW) – A Portage, Ind. man was found floating face down in Lake Michigan on Friday afternoon at Portage Lakefront Park.

Mark Tuthill, 47, was on the lake with four friends in a boat when the group anchored the vessel in chest-deep water, Department of Natural Resources Conservation Officer Gene Davis said.

The group played in the water about 30 minutes before three people separated from Tuthill and another person. Tuthill’s friends started to worry about his absence about 90 minutes later.

Davis said someone screamed when they spotted Tuthill’s body floating face down in the lake. Someone fished him out and started performing CPR, but they eventually determined that Tuthill was dead.

Officials believe he may have drowned, but the cause of death won’t be determined until a Monday autopsy is completed. Davis said officers doubted that Tuthill had a heart attack since his friends mentioned that he walked a lot and was healthy.

Davis said most of the water is chest deep in the area around the boat but there is a trough nearby that would have put the water above swimmers’ heads.

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