Baltimore, MD – WBAL-TV – Firefighters responded to a carbon monoxide scare Monday in Baltimore’s Hampden neighborhood.

Crews responded to a house in the 3400 block of Chestnut Avenue early in the afternoon. They found three residents suffering from carbon monoxide poisoning, WBAL-TV 11 News reported.

Two people were taken to Shock Trauma and the others to University Hospital. There’s no word on their conditions as of 5 p.m. Monday.

Fire investigators told 11 News that the carbon monoxide levels were extremely high and they do not know for sure what caused the leak.