A large sinkhole has collapsed part of the National Corvette Museum in Bowling Green, Kentucky, swallowing eight cars including the historic one millionth Corvette built in 1992.

The sinkhole, measuring 12 metres wide and up to nine metres deep, opened up early yesterday morning, in the domed section of the museum.

This CCTV footage shows the moment that the floor collapsed underneath the cars.

We had several employees in tears back there, Wendell Strode, the executive director of the museum is reported to have said.

"They’re here every day, they work with (the Corvettes), they take care of them."             

No injuries were reported, but a 1993 ZR-1 Spyder and a 2009ZR1 "Blue Devil" on loan from General Motors Co were among the iconic cars piled up in the gaping pit.         

Alarms went off early yesterday morning in the "Skydome" area and museum security officers who rushed to the scene discovered the sinkhole.            

Museum spokeswoman Laura Johnson said other cars near the sinkhole have been safely removed, and the museum was now trying to find a way to pull up the damaged Corvettes.
In addition to the White one millionth Corvette, a 1962 Black Corvette, a 1984 PPG Pace Car, a 1993 Ruby Red 40th Anniversary Corvette, a 2001 Mallett Hammer Z06 Corvette and a 2009 White 1.5 millionth Corvette were among the damaged cars owned by the museum.
Burton said the millionth Corvette, which was never sold,was likely the most valuable car and could fetch "several million dollars" from the right buyer.
The facility will be closed while a structural engineer assesses the damage, the museum said. It will reopen today, but the Skydome area will be blocked off.

That region of south central Kentucky contains many caves and sinkholes, known as "karst" topography. Mammoth Cave National Park is about 32km from Bowling Green.

Bowling Green city hydrologist Tim Slattery said when the museum was constructed, builders "did do their due diligence" on the area's geography. But sinkholes can develop over time, as water goes underground and carries soil with it, he said.

GM builds Corvettes at a plant near the museum, which opened in 1994.

The value of the damage was not immediately known, as most are one-of-a-kind collector cars with no similar sales figures to use as comparison, according to Sam Murtaugh, marketing director at Mecum Auctions of Wisconsin. 

"How do you even begin to place a value on the one millionth Corvette built?" Mr Murtaugh said in an e-mail. "It's irreplaceable."

Dave Chrisley, president and co-founder of the Bowling Green Assembly Corvette Club, which was started by plant workers, said he believes the cars on loan from GM were the most valuable -especially the Spyder.

"You'd have to auction it to even put a price on it," said Mr Chrisley. "I couldn't even give you a ballpark. It was a concept car."

The museum's Facebook page was filled with comments from devastated auto fans, including one suggesting that flags be lowered to half-staff "to honor the fallen vettes."