On March 4, 2012, at 0852 Pacific standard time, a Bowers Fly Baby 1-A, N41017, veered off runway 18 and collided with a hangar at Fallbrook Community Airpark, Fallbrook, California. The pilot operated the airplane under the provisions of Title 14 Code of Federal Regulations, Part 91. The private pilot was seriously injured, and the airplane was substantially damaged. Visual meteorological conditions prevailed, and no flight plan had been filed. No witnesses observed the accident. The airplane was found entangled with the structure of a T-hangar, the nose of the airplane embedded into the hangar, the tail protruding out, left wing broken from the fuselage, and the right wing folded up and over the open cockpit. The pilot was life flighted to a hospital with non life threatening serious injuries. On March 5, a Federal Aviation Administration(FAA)inspector examined the airplane, established control continuity, and found no mechanical anomalies. The inspector also noted that there were no witness marks in the shallow slopped grassy terrain between the edge of the runway and the hanger. About 600 feet from the end of the runway 18, a broken elevated runway edge light was identified. The left wing of the airplane showed evidence of impact damage by a elevated runway edge light. The pilot was interviewed by the FAA inspector, who reported that the pilot could not recall the events of the accident. A witness who arrived on-scene about an hour after the accident stated that at that time there was a modest 8-knot northerly wind. The pilot did not submit the National Transportation Safety Board Pilot/Operator Aircraft/Incident Report Form 6120.1/2.