THIBODAUX, La. (AP) — A 71-year-old man has died after his boat took on water and he was not wearing a life vest, the Louisiana Department of Wildlife and Fisheries said Friday.

John Sutton of Thibodaux was following another boat when his 15-foot vessel began to take on water about noon Thursday in Grand Bayou, a news release said.

The other boater turned to help and saw Sutton struggling to stay afloat, but he was unresponsive when the man grabbed him and brought him to shore, the statement said.

The man began CPR and called 911. Lafourche Parish sheriff’s deputies took over CPR when they arrived but could not revive Sutton.

The department said agents are investigating why Sutton’s boat took on water and why he went in.