Colchester police announced a 56-year-old Milton man died after suffering a cardiac event at a floating party on Malletts Bay on Saturday.

The unnamed man was participating in Raftapalooza off Thayer Beach in Colchester, police said.

At 3:12 p.m., Malletts Bay Fire tweeted a warning for all Raftapalooza participants to evacuate the area immediately.

When a strong thunderstorm struck around 3:30 p.m., police spotted a distress flare among the rafted boats. Colchester Technical Rescue and Malletts Bay Fire Department responded and found the man was in cardiac arrest, a press release said.

Colchester police and rescue crews continued resuscitation efforts on shore. Burlington Fire Department transported the patient, who died at the University of Vermont Medical Center in Burlington, police said.

The U.S. Coast Guard warned event participants to leave the area as the storm approached. The strong winds toppled tents and smaller rafts, and three anchored boats also struck one another, causing damage, police said. The heavy rain made it difficult for participants to leave safely, police said.

Another male was transported to UVM Medical for heat-related issues.

In the lead-up to Raftapalooza, which drew 3,000 participants last year, police heads and town administrators publicly expressed desire to exile the gathering, citing safety concerns.

“We are the rescue and emergency responders who would try to get the person out of the lake,” town manager Dawn Francis said at the July 12 selectboard meeting. “We are trying to discourage [the event] just because of the impact on the community that we just don’t have the resources for.”

The event organizers raised $5,000 to cover the cost of police and rescue services for the fourth annual event. Raftapalooza was permitted with the Coast Guard and had a safety plan for the first time.

Investigation into the man’s death continues, police said.