Two Alpharetta men in Lake Lanier drowned late Saturday when their pontoon boat wrecked in Forsyth County.

The bodies of Lung Mang, 21, and Tha Thang, 23, both of Honor Run in Alpharetta, were found in about 10 feet of water Sunday morning near the boat docks at Port Royale in Forsyth County, said Karleen Chalker, a spokeswoman with the Forsyth County Sheriff’s Office.

Mang and Thang were among nine people who had rented the pontoon boat for the evening. They included Mang’s sister and brother as well as other relatives and friends, Chalker said.

The pontoon reportedly wrecked while trying to return to Port Royale in a heavy rain and wind storm at about 11:30 p.m. Saturday, she said.

The boat’s driver reportedly hit an obstruction in the lake, although exact details of the wreck still are under investigation, Chalker said.

Seven of those aboard the pontoon boat were able to get to shore unharmed, Chalker said, but Mang and Thang did not.

Others aboard the boat stated the two men could not swim, and reports indicate that no one on board was wearing a life jacket, Chalker said.

One passenger was taken to Northeast Georgia Medical Center on Saturday night for treatment of a cut to his foot. He was treated and released, Chalker said.

A rescue mission was started immediately by units responding to the call, the Forsyth County Fire Department’s Dive Team, the Forsyth County Sheriff’s Office Marine Patrol Unit and the Department of Natural Resources, Chalker said.

However, the search was ended at about 1 a.m. Sunday because of darkness.

The fire department’s dive team began searching for the two men again about 9 a.m. Sunday and recovered the bodies of the men at about 10 a.m., Chalker said.

They were located near each other in about 10 feet of water, about 20 feet from the shoreline of a sandbar.

The Department of Natural Resources is investigating the incident but had no further updates Sunday evening.

The two deaths marked the third and fourth deaths on Lake Lanier this holiday weekend.

Two teens drowned on Lake Lanier in the first 48 hours of the holiday weekend. Dago Bento Mejia of East Meadow, N.Y., drowned late Saturday afternoon near Bell’s Mill Bridge. Ariel Cotuc Chaudjay, 17, of Duluth, drowned Friday at a park in Forsyth County.