Giuseppe Storniolo, 9, was at the Reservoir Park in West Allis, a Milwaukee suburb, with his parents, sister and brother when the slide he was on, made of a hollow tube of hard plastic spontaneously inflated and heated up, Fox News quoted local WTMJ as reporting.
"I just heard like a big explosion so I thought maybe something fell," Storniolo’s mother, Diana told the news station.
She ran over to the playground to see what happened and saw her injured son near the distorted slide.
The slide exploded for an unknown reason. Storniolo just so happened to be on the slide when it burst.
“It was like the slide had almost been inflated,” Dan Devine, mayor of West Allis, said. “It just opened up, bubbled.”
The young boy suffered second-degree burns on his leg due to the incident, his mother said.
Devine said the city took action immediately by closing the slide and then taking it down completely.
Police said the incident does not appear to be suspicious but officials are investigating why the slide exploded.
“We had been in touch this morning with the manufacturer, with the designer, the installer, none of them had never seen anything like this before,” Devine said.
"They have put these structures (slides) all over the world, in all sorts of climates, all different countries," he said.