SUGAR GROVE, Pa. — Thirty-four people are recovering today from carbon monoxide poisoning apparently caused by a blocked chimney in a northwestern Pennsylvania church.

The adults and children who got sick were attending church services and a social hour Sunday morning at Hessel Valley Lutheran Church in Sugar Grove Township, Warren County, which is along the New York border.

A young woman passed out during the church service and the church was evacuated when several people fell ill during the social hour and someone called 911.

Most were taken to Warren General Hospital, where four had to be flown to Pittsburgh for treatment, and six others to Women's Christian Association Hospital in Jamestown, N.Y.

Everyone is expected to recover.