A roller coaster derailed in Stockholm on Sunday, sending some passengers to the ground in a theme park accident that killed one and injured nine, police and park officials said.

Witnesses described a chaotic scene in Gröna Lund park where the front of the train appeared to jump off the tracks before coming to a stop, with one of the cars leaning towards the ground.

“The front of the train partially derailed and came to a stop on the track at a height of between 6 and 8 meters (between 20 and 25 feet),” said Jan Ericsson, the park’s chief executive. “There were a total of 14 people on board, of whom one person died and several others were injured.”

The district government said nine people were taken to hospital, one of them in serious condition. She added that three of the injured were children, all of whom had minor injuries.

Witness Ziba Asadi told Swedish broadcaster TV4 that she was standing directly below the roller coaster when she saw the wheelset of one of the two cars smash to the ground.

“Then the car stops and people fly out and fall out of the car,” she said.

Eyewitnesses said that two or three people fell out of the car and one of them managed to cling to the tracks. Pictures from the scene showed a man sitting on a crossbar below the stopped train.

“So he sits there on either side of (the crossbar) and waits,” Al-Asadi said. “There was complete panic.”

Park officials said the amusement park was evacuated after the incident and will remain closed for seven days to allow investigators to figure out what went wrong.

“This should not be allowed to happen,” Grona Lund spokeswoman Annika Trosselius said. “Safety is the most important thing for us. We would never open an attraction if we weren’t confident it was safe, so that’s something we need to investigate thoroughly.”

Police have opened a criminal investigation into possible charges of manslaughter, causing bodily harm and causing danger to others.

The 800-meter-long (2,600-foot) jet-ski was opened in 1988 and renovated in 2000, according to Grona Lund. It has a maximum height of 30 meters (98 ft) and a top speed of 90 kilometers per hour (56 mph).

Opened in 1883, Gröna Lund is Sweden’s oldest amusement park.