The Dane County medical examiner identified the body pulled from Lake Mendota on Friday morning as a swimmer who went missing earlier Friday.
Authorities said Matthew Roelse, 22, of Madison, likely died from drowning. The medical examiner said further testing is underway and a final ruling will be made once those results come back.
Madison police said his body was found at about 10:30 a.m. on Friday.
The discovery came after more than eight hours of searching. About 50 divers and two boats were searching the lake, after Roelse was reported missing at about 2:46 a.m. by a 22-year-old woman.
The pair had been swimming near the Memorial Union when Roelse went under the water. The woman attempted to help him to shore but called police when he didn't resurface.
The Madison Fire Department's Lake Rescue team and the Dane County Sheriff's Department’s dive team were among those searching for him.
Police aren't saying whether alcohol may have played a role in the incident, and that any toxicology reports will have further information.
Police said that they're advising people to be careful where they choose to swim.
"I think the big factor here would be if you're going to go swimming, you really need to do it in an area where people are nearby so if you have some type of problem, there are individuals around that might be able to help you," said Howard Payne, Madison police's public information officer. "This swimming ordeal happened sometime after 2 a.m. so it is definitely not peak time, if you will, to be swimming."
Some University of Wisconsin students said that the idea of late-night swimming is a common thought.
"I think it's something on everyone's bucket list to do before they graduate," said Amanda Wiener, a UW senior from Brookfield.
However, Wiener and friend Caitlin Flaherty both said the incident is scary and said that rather than crossing it off, it should be something to avoid.
"I think we should definitely tell students that (apparent drownings) are happening," said Flaherty. "I just heard about it a few minutes ago so I think it is something that students need to be aware of."