Authorities on Tuesday identified the Chicago man who drowned in Geneva Lake on Monday.

David R. Trehane, 40, drowned at a gathering with others who rented a pontoon from a local boat rental agency, according to a news release.

First responders showed up to the area near Stone Manor by pier 880 in Lake Geneva at about 5:05 p.m. Monday, the release states.

Witnesses told authorities that Trehane was swimming while the pontoon was drifting when he started to struggle, according to the release. He called for help, but others were unable to get the boat started to get closer to him.

People threw a life jacket toward him, but he could not get to it, according to the release.

Authorities from several agencies worked on finding Trehane until it became too dark, the release states. They then began searching again at 6:30 a.m. Tuesday until they found his body at about 7:55 a.m.

While the investigation is ongoing, the release says criminal charges are not expected for anyone from this incident.