A slide was removed from a Wisconsin playground last week after it bubbled up and exploded, injuring a child.
An investigation is underway into what could have caused a hole to form at the base of the slide at Reservoir Park in West Allis, and the victim's mother is waiting for answers, TMJ4 reported.
"It was just so confusing," Diana Storniolo told the NBC affiliate.
Nine-year-old Giuseppe Storniolo was with his younger brother and sister and his parents Wednesday evening.
"I just heard like a big explosion so I thought maybe something fell," Diana said.
She said her son suffered second-degree burns.
"I would like them to find out what went wrong," she said.
Somehow a hole formed near the bottom of the slide when the boy was going down.
"It was like the slide had just almost been inflated. It just opened up, bubbled," Mayor Dan Devine said.
Devine said the city secured the area right away. On Thursday morning kids were still playing around the caution tape before engineers took the slide down.
"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.
The mayor said there are tens of thousands of slides like the one in question out there.
"They have put these structures all over the world, in all sorts of climates, all different countries," he said.
Police have not opened a criminal investigation.
"I don't know. It might be some kind of chemical reaction. It might be some kind of gas plastic reaction," Devine said.
It's hard for parents to ignore what happened, TMJ4 reported.
"It's just weird that that would happen you know to a slide," said Andrea Schoenbeck, another mom.
However, families are still using the playground.
"Yes, I am until they fit it then it's safe," said Ilias Deliziannis, a grandfather.
City inspectors on Thursday checked two more slides in West Allis like the one removed from Reservoir Park Thursday and said they are safe.