Two riders fell 34 feet, and several others were injured after a roller coaster in Florida derailed Thursday.

The ride’s front car was completely off the tracks and dangling when firefighters arrived at the Daytona Beach Boardwalk in Florida on Thursday night. Two of the front car’s four riders fell while the other two were hanging from the ride, Sasha Staton, a spokeswoman for the Daytona Beach Fire Department, told reporters.

Fire crews rescued a total of 10 riders, six of whom were taken to a hospital. The two riders who fell were most seriously injured, Staton said, though she did not know more about the injuries.

Officials have not said what caused the ride to derail. Jennifer Meale, spokeswoman for the Florida Department of Agriculture and Consumer Services, said the agency’s inspectors conducted a “thorough inspection” of the roller coaster on the same day the accident happened, and the ride was found in compliance with state law.

“First and foremost, we’re concerned about the individuals who were injured last night. Their well-being and recovery is of the utmost importance,” Meale said in a statement Friday, adding later: “We have launched an investigation to determine the cause of the accident, and anyone who should be held accountable will be held accountable.”

A photo the fire department shared on social media showed the front car hanging down from the track while passengers in the other cars waited to be rescued. Staton said crews had to use a tower truck ladder to rescue the stranded passengers. One video showed two firefighters slowly guiding a rider as that person crawled along the ladder.

The three-car roller coaster is called the Sand Blaster, is 85 feet high and has more than a half-mile of track, the Daytona Beach News-Journal reported. The ride began operating at the boardwalk in 2013. It was manufactured in 1975.

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