On June 18, 2007, about 1930 eastern daylight time, a Cessna 172RG, N522GC, registered to and operated by a private individual as a Title 14 CFR Part 91 personal flight, incurred damage while landing at Lantana, Florida. Visual meteorological conditions prevailed, and no flight plan was filed. The private-rated pilot was not injured, and the airplane incurred substantial The flight originated in Daytona Beach, Florida, the same day, about 1720. The pilot stated that after entering the pattern to land at Lantana, Florida, and initiating prelanding procedures, it became clear to him that there was a problem with the landing gear. He said that the landing gear would not go down, and there was no green indication for the landing gear indicators. He looked out the left window and noted that the main gear was not extended, and that attempts at lowering the gear caused the circuit breaker to "trip." Pushing the circuit breaker back in was also ineffective in lowering the landing gear. He said he initiated emergency procedures to extend the landing gear, and in doing so the hand pump also failed to extend the landing gear. After recycling and pumping the landing gear for about 20 minutes, he said that it became clear to him that the landing gear would not extend. He said he did not know that the right main and nose gear were extended. Having completed three hours of flying, and with about one hour remaining before darkness, he said he made the decision to land the airplane on runway 15 at the Lantana Airport. During the landing the pilot said that he slowly brought the airplane to the ground so as not to cause a propeller strike, and later found out that the landing gear was partially extended, which caused the airplane to veer to the left, off the runway into the rough gravel and sand, during the landing rollout. Prior to this event the pilot said that the landing gear had been functioning flawlessly. The airplane incurred damage to the fuselage, wings, landing gear and tail section. After recovery the airplane was taken to a maintenance facility at the airport, and was examined by an FAA licensed airframe and powerplant mechanic. The inspection revealed that the hydraulic line on the down-lock side of the nose actuator had separated at the fitting, which had resulted in a total loss of hydraulic fluid, and the landing gear collapsing.