A New York state trooper died Tuesday from injuries he suffered when his police cruiser was rear-ended by a tractor-trailer shortly after he pulled over a car for speeding on the Thruway, authorities said. Trooper David Cunniff, 35, was inside his patrol car behind the car he had pulled over on Interstate 90's eastbound lanes around 8:20 p.m. Monday, when his cruiser was hit by the big rig and he was partially thrown from his vehicle.