Updated

BELLEVUE, Iowa -- Two runaway horses pulling a wagon trampled spectators at a small-town Fourth of July parade, killing a 60-year-old woman and injuring at least 23 other people, four critically.

The horses bolted Sunday after one rubbed its head against the other, removing that horse's bridle, police said. They galloped for several blocks with the wagon in tow, trampling parade-goers. The wagon flipped and ejected its two passengers, police said.

Among those injured were children who had stooped in the street to pick up candy that had been tossed to them.

Police declined to identify the woman who died, but said she passed away at the University of Iowa Hospital in Iowa City. Four people were hospitalized in critical condition, five others were seriously hurt and 14 others sustained minor injuries, police said.

The parade is a decades-long tradition in Bellevue, a town of about 2,300 people on the Iowa-Illinois border.