A young woman who promotes volunteerism for New York City is credited with pushing her friend out of a car's path before she was gravely injured herself.

Mayor Michael Bloomberg said Monday that "everyone in the city is pulling for" Erinn Phelan, and calls her a "fighter" with "a big heart."

The 22-year-old native of suburban Boston works for an agency called NYC Service.

Police are searching for the driver, who fled after the accident early Sunday in Brooklyn.

Fidel Guerrero, of Pharr, Texas, tells the New York Daily News that Phelan saved his daughter.

Alma Guerrero is in stable condition. She's a medical student at Brown University in Providence, R.I.

The women were roommates at Brown.