Fayetteville, N.C. — Four people were injured Thursday morning when a gas grill exploded at J.P. Riddle Stadium in Fayetteville, authorities said.

Authorities said employees were unaware there was a leak in a propane line inside the stadium. When they tried to light a commercial-size grill at about 9:50 a.m., it ignited the gas fumes.

"We heard a large boom. It sounded like a bomb went off, and everybody started running to the office," a caller told a 911 dispatcher while reporting the explosion.

"(It happened) so quickly. It was just crazy. It was like something you see in the movies, but you don't really understand it," said Eric Davidson, whose son was among the injured.

Jonathan Davidson, a recent Campbell University graduate, is working as a summer intern for the Fayetteville SwampDogs baseball team, which plays its games at Riddle Stadium, his father said.

"He was just there to deliver a message from the propane guy. How ironic," Eric Davidson said, noting his son and another intern were walking into the concession area to pass along the message when the grill exploded.

"They opened the door, walked into the doorway and all he saw was just a big ball of flame," Eric Davidson said.

Jonathan Davidson suffered second-degree burns on his legs, and he and SwampDogs manager Darrell Handelsman and team employee Mark Wilderman were sent to the North Carolina Jaycee Burn Center at UNC Hospitals in Chapel Hill for treatment. The fourth worker, whose name wasn't released, was treated at Cape Fear Valley Medical Center in Fayetteville and released.

"The gentleman that had lit the grill was in quite a bit of pain," Eric Davidson said.

The Fayetteville Fire/Emergency Management Department shut off gas lines to the stadium, at 2823 Legion Road, and firefighters spent several hours clearing gas fumes from the area.

The State Bureau of Investigation is assisting local authorities in investigating the explosion, but Fayetteville officials said the gas leak doesn't appear to be a case of foul play.

Stadium officials declined to comment Thursday, so it's unclear if the message Jonathan Davidson was relaying had anything to do with the gas leak.

Damage to the stadium was minimal, authorities said.

"We just appreciate folks' prayers," Eric Davidson said as he choked back tears. "It's one of those calls you don't want to, that you don't want to get as a parent, but they're OK."