Local authorities are continuing to search diligently for a Madison man who went missing while swimming in Lake Monona Wednesday night.

According to a statement from the Dane County Sheriff’s Department, sheriff’s deputies and the Madison Police and Fire departments responded to a call at approximately 9:40 p.m. Sept. 9 for a report of a missing swimmer in the lake.

The missing swimmer, Warren Roecker, 36, and the driver of the boat, Terry A. Stehr, 41, were on a boat between the Olin Park boat ramp and Monona Terrace. After the two went for a swim, Stehr returned to the boat but Roecker had disappeared.

Statements from the Madison Fire Department indicate their Lake Rescue Team searched the area for an hour, both on the lake and onshore.

When the rescue team got close to the men’s boat, they realized Stehr was in the water. The team then secured both Stehr and the boat, according to the statement.

Stehr was arrested later that night for charges of operating a boat while intoxicated, according to the statement. Elise Schaffer, spokesperson for the Sheriff’s Department, said both of the men had been drinking.

“One important thing to note is that Stehr was wearing a life preserver, while [Roecker] was not,” Shaffer said.

The Fire Department handed over the search to the Dane County Sheriff’s Dive Team later Wednesday night, who searched the area for several more hours.

Schaffer said while the Sheriff Department’s Dive Team took control, they did not search for the remainder of the night due to the darkness.

“Once it gets dark, it gets hard to search,” Shaffer said.

Schaffer added the dive team resumed the search at about 8 a.m. Thursday. The team is using sonar equipment to aid the search. Additionally, the rescue divers have been taking shifts, so there are two to three divers searching at a time, she added.

According to Schaffer, the search area runs the same portion of the lake the two men were located the night Roecker disappeared, between the Monona Terrace and the boat ramps at Olin Park.

Dane County Sheriff’s Department Sgt. Tim Elve said the plan is to continue the search today as well if Roecker is still missing.

Elve said at this point, the hope is that Roecker is still alive.

“I guess the best way to put it is to make sure he’s not out there (in the lake),” Elve said, adding he hopes he is somewhere else and is unaware anyone is looking for him.

Two separate emergency calls were made for the incident. The driver of the boat called 911 after Roecker went missing and a witness onshore heard a man scream on the boat, prompting another emergency call.

Wisconsin court records show Stehr was found guilty of operating under the influence in 2008.

As of press time, Roecker remains missing.