RIVERSIDE, Calif. (KABC) -- Half a dozen children were injured on a roller coaster ride at John's Incredible Pizza Company in Riverside on Monday, according to officials.Six children were on the small roller coaster when it experienced a mechanical issue, the Riverside Fire Department stated.Fire officials said the victims suffered injuries to their mouth and noses when the ride came to a sudden stop and the children were launched forward."We had a kids' roller coaster, we had a mechanical issue where one of the wheels fell off. Basically a children's roller coaster about 5 feet off the ground," Capt. Tyler Reynolds with the Riverside Fire Department explained. "They say it travels between 5 and 10 mph. Once that wheel fell off and came to that sudden stop, everybody was just launched forward."All the children had a lap bar on for safety and none were ejected from the ride. The six children were treated and released.Ryan and Elvira Reynolds said their two daughters were on the ride when it malfunctioned. They said one of their daughters was injured while the other was left shaken."Apparently the wheel broke off and the whole thing just stopped and all the kids bumped their heads," Ronald Reynolds explained."They were fine until a couple seconds later they started bleeding. My daughter and three of the other kids had blood coming out of their noses and one of the girls had a broken nose," Elvira Reynolds said.ABC7 reached out to John's Incredible Pizza Company for comment and management declined to provide a statement.