Updated

A teenager was decapitated by a roller coaster after he hopped a pair of fences and entered a restricted area Saturday at Six Flags Over Georgia, authorities said.

Six Flags officials are uncertain why 17-year-old Asia Leeshawn Ferguson of Springfield, South Carolina scaled two six-foot fences and passed signs that said the restricted area was both off-limits and dangerous to visitors, spokeswoman Hela Sheth said in a news release.

Authorities were investigating reports from witnesses who said the Ferguson jumped the fences to retrieve a hat he lost while riding the Batman roller coaster, said Cobb County police Sgt. Dana Pierce. Police have declined to release the teenager's name until an autopsy is completed.

Six Flags said it closed the roller coaster after the Saturday afternoon accident out of respect for the Ferguson's family.

Click here for more on the scene reporting from FOX News' Jonathan Serrie.

Police said the ride was going full-speed when the Ferguson was struck. The ride's top speed is 50 mph, according to the park's Web site.

No one riding on the roller coaster was injured, Sheth said. The teen was with another boy who also entered the restricted area but was not injured, Pierce said.

Ferguson and his parents were at the park with a group from the Oakey Spring Baptist Church near Springfield, S.C., police said.

In May 2002, 58-year-old groundskeeper Samuel Milton Guyton of Atlanta was killed after he wandered in a restricted area under the Batman roller coaster's path and was struck in the head by the dangling leg of one of the ride's passengers. The ride was closed for a day to allow the federal Occupational Safety and Health Administration to inspect the ride. It was deemed safe for passengers.

In June 2007, a teenager's legs were severed when cables snapped on the Superman Tower of Power ride at Six Flags Kentucky Kingdom in Louisville, Ky. Doctors were able to reattach Kaitlyn Lasitter's right foot, but she had to have some of her left leg amputated and subsequent surgeries.

State officials blame a faulty cable and slow response by an amusement park ride operator in the accident. Her family is suing Six Flags Kentucky Kingdom, claiming the park failed to maintain the ride and equipment and ensure riders' safety. The amusement park has denied liability in court filings.

Click here to read more on this article from MyFOXAtlanta.com.