- PHOTOS: Small plane collides with Naperville building
- STORY: Small plane crashes into Naperville gym
The National Transportation Safety Board cited the pilot's failure to abort a takeoff as the probable cause.
The pilot, Lloyd McKee, and his wife, Maureen McKee, were seriously injured in the October 6, 2010, crash.
Their single-engine plane crashed into the roof of the XSport Fitness center at 75th Street and Route 59.
The report also cites improper annual inspection of the aircraft and a hole in the plane's exhaust pipe as contributing factors.
Officials say that a pre-flight inspection failed to notice two critical engine malfunctions, which caused the crash.