A pedestrian was struck and killed in Nanuet Monday, and police are trying to figure out if the driver knew he left the scene of an accident. Witnesses say the victim was walking along Route 59 when he was run over by a tractor-trailer. New City resident Linde Nelson, 52, died at the scene. The driver of the tractor-trailer stopped, according to witnesses, but then took off and got on the New York State Thruway heading north. Police stopped the truck on the thruway near Suffern and interviewed the driver. They say they are not sure if the driver knew he hit the pedestrian. The thruway entrance ramp was closed and traffic backed up for hours Monday afternoon as police continued their investigation.