21 people were hospitalized during a carbon monoxide leak at 22 Oak St., in Bridgeport.

The incident occurred Saturday at around 2:45 a.m.

Officials say some residents exhibited symptoms of carbon monoxide poising.

In total, 21 residents were transported to St. Vincent's Hospital and Bridgeport Hospital for evaluation.

The levels of carbon monoxide were found to be 2100 parts per million.

In comparison, the U.S. Environmental Protection Agency says that average levels of carbon monoxide in homes with gas stoves are five to 15 parts per million.

Officials say the incident is still under investigation. However, a generator was found running in the basement, which was the cause of the extremely high levels of carbon monoxide.

The Bridgeport Fire Department reminds residents when using a generator to keep it outside and away from enclosed spaces like homes, garages, and crawl spaces.

Carbon monoxide from generators is colorless and odorless and can be deadly.

Residents can call the Bridgeport Fire Department at 203-335-8835 to have a free smoke alarm installed.