A Cessna Citation 525 was substantially damaged when it went off the end of a runway on Saturday morning and came to rest partially submerged in a pond. The twinjet, on a Part 91 flight, was attempting a landing on 4,000-foot-long Runway 23 at Spruce Creek Airport in Daytona Beach, Fla. None of the three people aboard was injured in the accident. Spruce Creek is one of the largest fly-in communities, with nearly 5,000 residents, 1,300 homes and 700 hangars.