Three children were burned  Saturday night while they walked in an Orem, Utah, parade after the firing of a cannon accidentally set off a secondary explosion, according to news sources. The children, believed to be between 10 and 12 years old, were rushed to a local hospital and were  listed in stable condition Monday with first- and second-degree burns in the latest report on their condition.

They were part of a Civil War reenactment group which was participating in an annual parade celebrating Summerfest in a town about 45 miles south of Salt Lake City. According to bystanders, when the cannon was fired, sparks from the explosion landed on a nearby pouch containing more charges for the cannon, and that created a fireball with a lot of thick smoke.

“There were kids lying on the ground,” one onlooker told reporters. “One girl was hopping on one foot and there was overall shock.”

A nurse in the crowd rushed forward and began pouring water on the children’s burning clothes from water bottles that were thrown to her and then pulled  their clothes off them. Paramedics arrived shortly thereafter and the children were transported to a hospital.