Shortly before 6 p.m., two firefighters and two police officers went into the locked house to do a welfare check on the resident, Assistant Fire George Gomola said.
They found a deceased 70-year-old man and a note indicating that chemicals had been used, Gomola said. The man appeared to have died of exposure to chemicals, he said.
The responding officers and firefighters did not exhibit any symptoms of illness, but all four were taken to the hospital for possible contamination, Gomola said.
"They found clear signs of possible contamination inside," Gomola said. "A very small amount of chemicals are present." Fire officials would not confirm what the chemicals were used but said no hazardous materials had been released into the neighborhood.
Officials set up a hot zone around the perimeter of the home. The roads are blocked from South Benson Road, to Clinton Street to Oyster Road near Jennings Beach.
The Fire Department called in the Fairfield County Hazmat Crew and the Department of Energy and Environmental Protection. The crews were working to clean the scene and remove the body.
The man was last seen alive on Friday, said Deputy Police Chief Chris Lyddy. Police would not confirm his identity until notifying his next of kin.
Assistant Fire Chief Christopher Tracy said the incident began as a welfare check. A friend who hadn't seen or heard from the resident called police and asked them to check the house, police said.
Click here to follow Daily Voice Fairfield and receive free news updates.