Caribbean Atlantic Airlines Flight 340, a Douglas DC-9-31, N938PR, was involved in a landing accident at Saint Thomas-Harry S.Truman Airport, Virgin Islands. The aircraft, on its landing rollout, continued 323 feet beyond the far end of runway 9, and came to rest in an automobile repair shop, after striking several vehicles. There were 114 passengers aboard and a crew of five. Evacuation of the aircraft was orderly, with one passenger sustaining minor injuries. Three occupants of the ground vehicles, which were struck by the aircraft after it left the runway, were seriously injured and one was slightly injured. The weather in the vicinity of the airport had been characterized by intermittent rain showers from early in the morning through the time of the accident, and a total of 2.74 inches of rain was recorded for the 24-hour period. The existence of a considerable amount of standing water on the runway was corroborated by witnesses who stated that the aircraft was churning up heavy water spray on its rollout and did not appear to be decelerating very rapidly . Near the end of the runway, the aircraft was observed to be fish-tailing which was accompanied by loud sounds of engine reversing and associated popping noises. White tire streaks, typical of those observed in cases of known hydroplaning, were observed in the last 1,400 feet of runway, leading; off the runway into the aircraft tire tracks in the wet, sodded area between the runway and the street. PROBABLE CAUSE: “The loss of effective braking action caused by dynamic hydroplaning of the landing gear wheels on a wet/flooded runway. Contributing factors were a higher-than-normal touchdown speed and the location of the airport and its topography which permitted excess levels of water to accumulate on the runway.”