A pontoon flipped on a small west-central Minnesota lake, fatally trapping one of the three men who were aboard authorities said.

The incident occurred about 8:45 a.m. Friday on the lake known as Golden Pond, located a half-mile east of Sunburg, according to the Kandiyohi County Sheriff's Office.

Killed was Philip L. Thissen, 76, of Clara City, Minn., the Sheriff's Office said.

According to authorities:

Emergency responders arrived to find the 14-foot pontoon upside down. Two men who were on the pontoon reported that Thissen was trapped underneath the pleasure vessel for about 20 minutes.

Divers with the Sheriff's Office removed Thissen and determined that he was dead.

The other two on the pontoon were identified as Jerry R. Anderson, 76, of Prinsburg, Minn., and Gordon M. Rothwell, 72, of Clara City. Neither was harmed during the incident.

Authorities have yet to say how the pontoon flipped.