The incident occurred in Danbury at around 10:30 p.m. on Monday, July 16, at Candlewood Lake in the area of City Island.
According to Erin Henry, spokesperson for the Danbury Fire Department, it was reported that two men had jumped off a boat into the lake and disappeared.
Henry said rescue crews immediately began search and rescue efforts, using boats equipped with sonar and underwater imaging equipment to help locate the men.
Henry added that the search was suspended around 2:30 a.m. on Tuesday and will resume early.
Mutual aid dive teams from Danbury Police, Brookfield Police, NUSAR, and Region Five manned the search.
Additional rescue boats from Brookfield, Sherman, New Fairfield, Candlewood Lake Authority, and Ball Pond responded to assist.
The Brookfield Police Department's air drone was also deployed.
The Salvation Army and Danbury Volunteers from Squad 19 and Squad 31 provided scene support.
The state Department of Energy and Environmental Protection is leading the investigation.
This is a developing story. Check back to Daily Voice for updates.
Click here to follow Daily Voice Haddam-Killingworth and receive free news updates.