(CNN) -- An accident on a swing ride at a Connecticut festival Sunday injured 13 children, some seriously, according to police.
The ride "apparently lost power causing the children on the ride to forcefully fall to the ground," police in Norwalk, Connecticut, said on the department's Facebook page.
Most of the injuries were minor, police said, but several were seriously injured, "including two which appeared to be the most serious."
Deyo Ello told CNN affiliate News 12 Connecticut that he watched in horror from the Ferris wheel line.
"It was a big boom, a big crash, three or four times over," he said. "They slammed into the base of (the ride), and then you heard a whole bunch of screaming."
Ello tried to go on the ride with his daughter, but they were turned away when she didn't meet the height requirements. Seeing injured children lying on the ground after the accident was devastating, he told News 12.
"If she was tall enough, that would have been her," he said, grabbing his daughter's hands. "My heart is broken. I'm speechless. It ruined the day, you know."
The accident occurred at Norwalk's annual Oyster Festival.
In a statement on its Facebook page, the Norwalk Seaport Association, the festival organizer, said the well-being of the children and families involved was its only concern.
The festival temporarily shut down rides after the accident but reopened them Sunday evening after fire investigators and the ride company inspected them.
"We are cooperating fully with the investigating authorities," the association said. "Any further questions should be directed to them."
Stewart Amusement, which owns the rides, could not be immediately reached for comment. The company's owner told News 12 Connecticut that he is cooperating with investigators. The swing ride was inspected by state officials on Friday and deemed to be safe, he said.
CNN's Rick Martin contributed to this report.