Clarkstown Police need your help tracking down a hit and run driver in a fatal accident from early this morning. Police say 40 year-old Katrina Grigsby of Nyack was walking alongside the southbound lanes of Route 9W near Rockland Lake North around 3:55 AM when she was struck by an unknown vehicle that fled the scene. While a witness was on scene a second vehicle struck the victim and fled, but was later found in Haverstraw. The driver of that vehicle has charges pending against him at this time. The Clarkstown Police Detective Bureau is working the case, and seeking information on the first vehicle that struck the victim. Anyone who may have been in the area and has any information or video of any passing vehicles from 3:30 – 4:00 AM, contact the Clarkstown Police at 845-639-5800.