Courtesy National Corvette Museum
The sinkhole swallowed eight priceless 'Vettes, including two on loan from General Motors.
Watch a camera drone survey the damage.

Engineers probing the cause of a massive sinkhole that formed underneath the National Corvette Museum and swallowed eight rare cars have mobilized helicopter drones as a key inspection tool, underscoring the importance of the emerging technology in construction forensics.

"There is a cave that they have found in there with the drones," Katie Frassinelli, a spokeswoman with the Bowling Green, Ky.-based museum, tells ENR.

Engineers at Western Kentucky University brought in the multi-rotor drones, each fitted with an onboard camera, the day of the accident. The footage can be viewed on the museum's YouTube channel.

Along with the school, engineers with K&S Engineering, Clarksville, Tenn., and local geotechnical consultant DDS Engineering have been retained to evaluate the building, which was deemed safe to enter shortly after the floor over the sinkhole partially collapsed, say museum officials. The museum was built 20 years ago at a cost of $10 million; a museum expansion, costing another $10 million, was completed in 2009.

The sinkhole, which formed on the morning of Feb. 12, developed under the floor of a 12-story-tall, circular atrium the museum calls the Skydome, part of the original structure. Photos of the 40-ft-dia, 30-ft-deep sinkhole show the eight Corvettes scattered inside the hole as if they were toys in a sandbox.

The damaged cars include a 1993 ZR1 Spyder and 2009 ZR1, both on loan from General Motors, as well as a classic 1962 'Vette and a 1992 Corvette, the millionth such car produced. All the cars are insured against damages, museum officials confirm.

The museum will reopen on Feb. 13, but the Skydome will remain closed. Local contractor Scott, Murphy & Daniel LLC, which built the original structure, has been retained as construction manager for the recovery and rebuilding project, say museum officials. The cause of the sinkhole is likely a karst formation, they add.

"It's not unusual for these sinkholes to happen in Kentucky," Frassinelli explains. "But it is unusual to happen at a national car museum."