MINNEAPOLIS (WCCO) — An 83-year-old Twin Cities man drowned Tuesday after he fell off a boat on a central Minnesota lake.

The Wright County Sheriff’s Office says Robert Jacobson, of Elk River, was riding in a boat on Granite Lake, about 50 miles west of the metro area, when he fell into the water around 3:20 p.m. He was not wearing a life jacket.

The boat’s driver jumped in the water to help Jacobson, but couldn’t hold him above water. Another boater stopped to help and was able to hold Jacobson above the surface until more help arrived.

First responders pulled Jacobson from the water and attempted life-saving efforts. A medical helicopter also responded. However, Jacobson was pronounced dead around 4:30 p.m.

The boat’s driver, a 76-year-old Annandale man, told investigators that he had stopped the boat out on the lake and put the motor in reverse to clear out weeds. When he shifted the motor back to forward, he noticed Jacobson was in the water.

The driver said he threw a life jacket to Jacobson, but Jacobson did not try to grab it.

The incident is under investigation by the sheriff’s office and the Midwest Medical Examiner’s Office.