WEST GARDINER — A Lisbon man died Monday morning after he suffered a medical event and fell overboard while fishing on Cobbosseecontee Stream.

Chadd Brewin, 33, of Lisbon, was fishing on a boat near the West Gardiner-Litchfield line with his father-in-law Claude Latouche, 67, of Lewiston when Brewin suffered an apparent medical event around 10:45 a.m. and fell off the boat into the water, Mark Latti, communications director for the Maine Department of Inland Fisheries & Wildlife, said in a news release.

Latouche attempted to get Brewin back on board, but he was unable to. Instead, he held onto Brewin and used the boat to bring him to the shore. While doing so, the boat overturned, and both men were in the water not far from the shore. Latouche was wearing a life jacket, Latti said. Brewin had a life jacket but was not wearing it.

Gardiner Rescue and the Maine Warden Service responded, and emergency personnel attempted to perform life-saving measures before Brewin was transported at 12:30 p.m. to MaineGeneral Medical Center in Augusta, where he died from the incident.

The Maine Warden Service is investigating the incident. It is unclear what type of medical event caused Brewin to fall overboard.

The Kennebec County Sheriff’s Office and West Gardiner Fire Department also responded.

Cobbosseecontee Stream flows through 15 communities in southern Kennebec County including West Gardiner before it connects to the Kennebec River.