Rescue teams recovered a Gwinnett County man’s body from the Chattahoochee on Tuesday night, more than 20 hours after his empty kayak was spotted floating down the river.

Friends of David Southin, 41, of Lawrenceville, told Channel 2 Action News the search ended late Tuesday when his body was pulled from the water. It was located by the Gwinnett fire department’s swiftwater rescue team and turned over to the Fulton County Medical Examiner’s Office, according to a spokesman for the Georgia Department of Natural Resources.

“The cause of the incident is under investigation and that investigation will likely take a few weeks,” Mark McKinnon with DNR law enforcement said in an email.

The search began in the dark Tuesday morning near the Forsyth-Gwinnett county line. Divers with Forsyth County’s swiftwater rescue team located Southin’s unmanned kayak in the water about 1:30 a.m. According to Southin’s family and friends, he had been fishing in the Suwanee area the day before and lost touch with his wife.

Rescuers from the DNR, the National Park Service and both Forsyth and Gwinnett counties joined in the effort to locate him. Initially, Gwinnett rescuers tried to use infrared technology to find the kayaker but were not successful, according to fire department spokesman Lt. Donald Strother.

About two hours into the search, divers were forced to pause the mission. Fog and darkness had hindered their ability to move any further, Strother said. They resumed at 8:30 a.m.

Crews did not recover Southin’s body until after nightfall.