A 23 year-old Spring Valley man was killed Friday night and two others were hospitalized after the pickup truck they were riding in rear-ended a tractor-trailer on the Garden State Parkway extension in Rockland. State Police say 48 year-old Edgar Vega of Harrison crashed into the tractor-trailer, which was preparing to exit the parkway. Police say Luis Vega was not seat belted and was ejected from the pickup and declared dead at Westchester County Hospital. Edgar Vega was taken there with serious injuries. Another passenger, 70 year-old Maria Vega of Spring Valley, was taken to Nyack Hospital with non-life threatening injuries. The truck driver was uninjured.