SACRAMENTO (AP) — Authorities have arrested a Northern California man who is accused of trying to kill himself and his two children with carbon monoxide.

The Sacramento’s Sheriff’s Department says deputies found 38-year-old Charles Lee Ewers and his two children inside a running car with a hose attached from the vehicle exhaust to the interior.

The department says the children, ages 8 and 10, were semi-conscious and both had signs they had been physically assaulted. They were taken to a hospital where they remain in serious but stable condition.

Officials say Ewers was arrested Tuesday on charges of attempted murder and felony child endangerment. He is being held without the possibility of bail.

Deputies went to Ewers’ home on Saturday after the children’s mother called police because he had failed to return them from a scheduled visitation.