Ryan was a backseat passenger in a car struck by the motorcycle late Saturday afternoon on Connetquot Avenue in Islip Terrace, police said. Police said she was taken to Southside Hospital in Bay Shore, where she later died.
The motorcyclist, identified by police as Christian Vogel, 24, of Central Islip, was critically injured in the crash.
Police said the driver of the car, Brandie Raynor, 24, of Willow Street, Central Islip, and two male passengers were not injured in the incident, which occurred at 5:23 p.m.
Police said Raynor was driving a 1998 Nissan Altima and was attempting to turn into a strip mall when the collision occurred. The motorcycle, a 2007 Yamaha, struck the rear passenger door of the vehicle.
Third Precinct Det. Sgt. Jeffrey Walker told Newsday that a preliminary investigation suggested Raynor was at fault because Vogel had the right of way.
Walker said, however, it appeared there was no criminality involved in the crash.
Vogel suffered a broken leg, broken hand and head injuries in the crash, police said.
With Matthew Chayes