A mother watched in horror as her son's pants went up in flames.

She said his iPhone unexpectedly began to smoke and melt, causing first- and second-degree burns.

NewsChannel 5 on Your Side has been following cases of exploding smart phones for months. While it's happened across the country, this is one of the first documented cases that's occurred in the St. Louis area.

"We were panicking and freaking out. I'm like 'Oh my god, my son is on fire!'" said Michelle Terry of St. Peters.

A fire in Ronnie Moore's pants ended his family's Fourth of July celebration.

"I just felt a sharp pain on my thigh," said Ronnie Moore, 21, Burned by his iPhone 6.

"I started hearing sizzling, and I'm like 'You're on fire,' and he's like 'Mom I'm on fire,' and I'm like 'Get out of the truck, get out of the truck!'" said Terry.

Moore says he threw his pants off and smoking pieces of his iPhone fell out of them.

"It was on the ground and it was just bubbling, there was smoke everywhere," said Moore.

"I have no idea what could've happened, what could've caused that," said Terry.

Experts say there are a few things that can cause an iPhone to explode and they all have to do with the lithium battery. Charging your Smart Phone with a cheap cable, dropping or damaging the phone, and getting it wet are some of the things that can cause your Smart Phone to sizzle. The battery may swell before any combustion.

But Moore says none of those things preceded the incident, although his phone did stop charging hours earlier.

He was taken to the hospital with first- and second-degree burns, and plans to file a complaint with Apple. He says he may stick to landlines now.

"I don't want another iPhone after this situation," said Moore.

"I really don't want anyone's life in jeopardy. I praise god that my son survived, it could've been worse. But I think we need to bring this to the public's attention," said Terry.

In other cases around the country, smart phones have caught fire while charging, or under pillows, even thousands of feet above the ground on an airplane.

We reached out to apple for a comment and while they couldn't comment specifically on Ronnie's case, they say this is not a common occurrence. But there are dozens of documented cases around the country, according to the Consumer Product Safety Commission.