A man who was stabbed in the chest while trying to help a woman in downtown Providence last weekend has been identified as a physical education teacher. Police told The Providence Journal that Central High School teacher David Taveras, 25, barely survived Sunday’s stabbing. Authorities said he left a party early Sunday morning and saw a woman he knew caught in a fight in a parking lot off Mathewson Street. Police said he was stabbed deep in the chest when he pulled her out of the fight, and the knife struck his heart. Detectives are looking for the attacker.