There are still many questions about an incident at Six Flags Great Adventure Thursday evening that left more than a dozen people injured on a popular roller coaster.

Six Flags confirms that several people reported experiencing back pain and minor injuries after riding on the El Toro roller coaster. Park officials say that 13 people were evaluated at the park – five of them were taken to a local medical facility for evaluation and treatment.

El Toro is now closed for inspection and possible repairs.

This is not the first time Great Adventure has had to shut down rides. The company was fined $5,000 last year after there was a partial derailment and did not tell the state Department of Community Affairs.

All amusement parks, carnivals and festivals in New Jersey must follow strict state guidelines to be allowed to operate.

News 12 New Jersey had a firsthand look at some of these safety procedures at Jenkinson’s in Point Pleasant Beach. The Pirate Plunge ride was just sent up when there was thunder and lightning. It was immediately sent back down.

“Safety is always a top priority for our guests and our staff here,” says Jenkinson’s Boardwalk manager Lisa Lightbody.

Lightbody says that whenever there is an incident at another amusement park, she is reminded how important safety policies are, whether the incidents are weather-related or mechanical.

“The maintenance department checks rides daily. The state checks it before we open for the season and can pop in at any time to check throughout the season,” she says.

The New Jersey Department of Community Affairs oversees carnival and amusement park safety and does those annual inspections and pop-up checks. They require rides to be certified and insured.

Regarding the Great Adventure incident – riders reported that it felt like they hit a pothole. It was then reported that the coaster jerked forward just as people were getting off.