Chicago, IL- Six people, including two children, were taken to area hospitals after becoming sick from carbon monoxide poisoning and called 911 after a CO detector went off at their Gage Park home, a Fire Department spokesman said.

Fire crews were called to a home in the 5800 block of South Sawyer Avenue about 7:20 p.m. because a carbon monoxide detector went off in the home. Crews found carbon monoxide levels of 350 parts per million, said Chicago Fire Department spokesman Chief Joe Roccasalva.

Four adults and two children were taken to either Holy Cross Hospital or St. Anthony Hospital in fair-to-serious but stable condition, Roccasalva said. All of those in the home were beginning to show symptoms of carbon monoxide poisoning, he said.

The levels of CO were high enough that the poisoning could have been fatal if the CO detector had not been working, Roccasalva said.

Officials were investigating the cause of the CO leak, and were awaiting the help of Peoples Gas, he said.