On May 3, 2005, about 2100 central daylight time, a Piper PA-31T, N2338V, piloted by a private pilot, was substantially damaged during an emergency landing on runway 21 (6,600 feet by 100 feet, asphalt) at Bismarck Municipal Airport (BIS), Bismarck, North Dakota. The flight was operating under 14 CFR Part 91 on an instrument flight rules (IFR) flight plan. Visual meteorological conditions prevailed. The pilot and passenger reported no injuries. The flight departed Jeffco Airport (BJC), Denver, Colorado, at 1630 with an intended destination of Bowman Municipal Airport (BPP), Bowman, North Dakota. In his written statement, the pilot noted that when he attempted to lower the landing gear on approach to BPP nothing happened. He elected to divert to BIS due to additional capabilities and assistance available there. The pilot stated that he executed the emergency gear extension procedure outlined in the pilot's operating handbook. However, this procedure was not successful. He reported that the nose landing gear was in a "dragging/trailing" position when observed through the engine cowling site mirror. He noted that the red gear unlocked indicator light was illuminated and the green landing gear down/locked indicators were not illuminated. The pilot noted that the BIS tower controller informed him that the left main landing gear appeared to be fully extended, the nose landing gear was in a "dragging" condition, and the right main landing gear was retracted. Since no further options were available to extend the gear, the pilot prepared for and executed an emergency landing. He noted that the airplane touched down on the left main wheel which did not collapse initially. The right wing subsequently dropped and contacted the runway. The pilot reported that he applied the left wheel brakes, however, the airplane departed the right side of the runway pavement and came to rest in the grass. The left main landing gear collapsed and a runway light was damaged in the process. The post-accident inspection revealed that a hydraulic powerpak drain line (Piper part number 46138-00) was ruptured. The drain line was located in the nose section of the airplane, forward of the cabin pressure bulkhead. The rupture was approximately one-half inch long. Hydraulic fluid was observed in the vicinity of the line rupture. The hydraulic reservoir was empty.