On June 22, 2012, about 1740 central daylight time, the landing gear of a Piper PA-46-310P, N43840, collapsed on landing at Metropolis Municipal Airport (KM30), Metropolis, Illinois. The pilot, the sole occupant on board, was not injured. The airplane was substantially damaged. The airplane was registered to and operated by Ware Resources, LLC, Martinsville, Illinois, under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a business flight. Visual meteorological conditions (VMC) prevailed at the time of the accident, and no flight plan had been filed. The cross-country flight originated from Nashville (KBNA), Tennessee. The pilot reported lowering the landing gear and observing three green annunciator lights. The airplane touched down on runway 36. Shortly thereafter, the nose gear collapsed. The airplane began drifting to the left and the right main gear collapsed, followed by the collapse of the left main gear. Post-accident examination revealed firewall damage and a compromised pressure vessel. The fixed base operator at Metropolis Municipal Airport recovered the airplane and examined the landing gear. They reported the landing gear handle was in the UP position (the pilot said he may have hit the handle inadvertently when the nose gear collapsed and he was thrown forward). The hydraulic reservoir was full and no sign of leakage. The airplane was placed on jacks. When the emergency extension handle was pulled, the main gear came down. The left main gear locked and the right main gear locked after a slight push. After the nose gear doors were removed, the nose gear came down and locked. The landing gear was not cycled due nose gear steering damage. The landing gear selector handle was moved to the DOWN position and proper travel at the selector valve was noted.