Family members react as they watch investigators at the scene of a fatal accident Tuesday on Roosevelt Boulevard in Philadelphia. Investigators say a 27-year-old woman was in a crosswalk with her four sons when they were hit by a car. The mother and two of her sons were killed in the accident. The woman’s two other sons, ages 4 and 5, are in critical condition. Philadelphia police are investigating whether cars may have been drag racing at the time of the crash.