WATERVILLE, Maine — There were two carnival ride accidents in Waterville over the weekend. Three children suffered bumps and bruises after the roller coaster ride they were on became unhitched Friday.

A woman also went to the hospital on Saturday after she unbuckled her seat belt on a different ride. In that case, investigators said rider error was to blame. Officials said both rides just passed inspection.

The rides have been taken down at Head of Falls Park, but the investigation is ongoing to find out why a hitch on the “Dragon Wagon” malfunctioned.

Squeals of delight on the Dragon Wagon quickly turned to cries for help. The incident was caught on camera Friday evening.

State Fire Marshal Joe Thomas said the hitch was replaced a year ago, and the ride had just passed inspection two days earlier.

“It was inspected on Wednesday, met all of the criteria we go by, operated all day Thursday, operated Friday up until the event when it came apart,” Thomas said.

Thomas said his office inspects all amusement rides once a year when they are first setup.

“We’re doing visual inspection to the manufacturer’s recommendations to make sure all parts and pieces that put that ride together to make it operate are in place and according to their recommendations,” Thomas said.

Thomas has six inspectors who are nationally certified. They use a form to make sure each ride meets the criteria. Sometimes, repairs need to be made before the rides can run.

Thomas said the latest inspection report for the Dragon Wagon is tied up in the investigation. “It had to have a couple of things; I know one car had to have a new safety belt put in it,” Thomas said.

Thomas said mechanical failures are rare and in the case of the Dragon Wagon, more frequent inspections wouldn’t have made a difference.

“If people wanted things done every time that ride is setup, I’m gonna be out of the fire marshal’s biz and just doing amusement devices here,” Thomas said.

CBS 13’s call to Smokey’s Greater Shows, which operates the rides, was not returned. They are scheduled to have rides in Old Town this weekend, but the Fire Marshal’s Office said the Dragon Wagon will not run until it’s fixed and re-inspected.