At about 1830 eastern time, a Piper PA-601P was damaged during takeoff from Manassas Regional Airport. The pilot was not injured. The pilot said the takeoff roll was normal up to about 65 knots. At that point, he felt a shudder that seemed to come from the wheels. He attributed it to standing water on the runway. Within a second he felt a second shudder and started having problems with directional control. He aborted the takeoff and the airplane yawed and departed the runway within two seconds. The airplane slid about 1,000 feet through wet grass before coming to a stop in a ditch. The pilot also reported it had snowed two days earlier and it had rained steadily on the day of the accident.