Long Beach Fire Department spokesman Steve Yamamoto says Shaunakaye Williams was unresponsive when friends pulled her from the water Friday night at the Courtyard Marriott in downtown Long Beach.
Emergency responders attempted to revive her but detected no pulse. The girl was later pronounced dead at a hospital.
Williams, a junior at Newark's West Side High School, was in town with classmates to compete in a regional robotics competition. Her mother, Paula Watson, told The Star-Ledger of Newark that her daughter could not swim.
Los Angeles County coroner's officials were scheduled to perform an autopsy on Sunday.