Orlando, Fla. - NASCAR officials claim an electrical fire caused a fatal plane crash near Orlando last year that killed two aboard the aircraft and three on the ground, but federal investigators do not necessarily agree with that claim.

The NASCAR accident summary is included in Friday's release of reports by the National Transportation Safety Board into the July 10 crash of the NASCAR airplane. It claims the pilots were overcome by fumes and were incapacitated.

The NTSB says it is still investigating the crash, with a final report of the cause likely in the summer. NTSB reports say a radar unit malfunctioned and caused a burning smell the day before the crash, but NASCAR claims the radar unit did not cause the fire that led to the crash.

NASCAR's insurance company earlier this year reached a settlement with a man whose wife and 6-month-old son were killed when their home was hit by the plane. The crash also killed NASCAR pilot Michael Klemm and the husband of a NASCAR executive, as well as a 4-year-old child in the second house that was hit.