Witnesses at San Jose's Christmas in the Park Sunday afternoon told of hearing "a few big bangs and then a pop."
"And then we looked up, and one of the carriages on the Ferris wheel was swinging," Dawn Seward, who was there with her 8-year-old daughter, told the San Jose Mercury News.
She said she say "a big chunk" of the ride fall off.
"I was shocked that no one was hit," she said.
Butler Amusements, operating 20 rides at the annual downtown holiday festival, confirmed no one was injured but said the wheel had to be reversed to allow one adult and child off the ride.
"We have had no problems with that ride -- or any other ride," Butler Vice President of Operations Lance Moyer said.
The operator closed down the ride "the minute it happened," he said.
An inspection found a rivet holding a box attached to an 8-foot-long string of LED lights on one of the wheel's arms had come loose, he said, and it fell, taking the lights with it and hitting the canopy of a carriage below,
That broke off a 10-inch piece of fiberglass that fell to the ground, he said.