No one was injured in the Saturday fire at the museum in Wayne County's Van Buren Township, 25 miles west of Detroit.
The hangar at Willow Run Airport was built by Henry Ford to produce World War II bombers on assembly lines like those used at his auto plants. The cause of the fire remains under investigation. Damage was estimated at $5 million to $7 million.
Fire hazards and structural problems have been known for more than three years. The museum announced in July that it was raising money to deal with the risks.
``We made choices,'' chairman Jon Stevens told The Detroit News for a story Tuesday. ``We never felt the public was at risk, but we knew we were keeping some very precious things in that old toy chest.''
Volunteers managed to rescue three rare, still-flying, World War II vintage airplanes from the building. The museum's large outdoor display of nonflying aircraft was unharmed.
The structure of the building was inspected in May 2003 and approved as safe for public use, said township planning director Bryce Kelley.
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