By Eric Miller, WRAL multimedia journalist

La Grange, N.C. — In Lenoir County tonight, a brush fire turned tragic. Three people are in the hospital and one is dead after commercial-grade fireworks detonated on a small farm.

Dozens of firefighters remained on the scene Friday night after seven hours.

Those firefighters dealt not only with hot spots, but unexp​loded fireworks scattered across a smoldering field.

For firefighters and neighbors alike, it was an unprecedented scene in Lenoir County.

What started as a controlled burn in a hay field quickly got out of hand.

Authorities said at approximately 3:15 p.m. Friday afternoon, La Grange Volunteer Fire Department, North Lenoir Fire & Rescue, and the North Carolina Forest Service were dispatched to 4871 Bulltown Road in La Grange, NC for a reported brush fire approaching a structure.

Crews were alerted by the Lenoir County 911 Center that the structure contained commercial-grade fireworks.

Shortly after arrival, authorities said fireworks detonated causing several injuries and damage to fire department equipment.

Micah Monroe saw it all unfold from the seat of his car.

“The explosion was massive,” said Monroe. “It was a tremendous bang and followed with little after shocks … that we now know were fireworks.”

A blackened wreck all that remains of a pile of hay bales, and a shipping container filled with commercial-grade fireworks.

“There was this extreme explosion that shot well over, I’d say 6-700 feet in the air,” said Monroe.

Fire officials said the explosion injured three firefighters, one critically, and killed someone who worked on the farm.

“They were trying to attack the fire as quick as they could to keep it away from the container, unfortunately it just got too hot before they could actually make that attack,” said officials at the press conference.

Fire officials confirmed this was a licensed fireworks op​eration. They’ll be investigating whether those fireworks were stored properly.

And what caused the deadly blast.

“We’re assuming that the contents of the container got so hot, it just detonated on its own,” said officials.

The investigation will start bright and early Saturday into what caused the fire, including representatives from the ATF and SBI.

Local fire departments across the area showed their support for those involved in the explosion.

The fire is under control, crews continued working into the evening to fully extinguish hotspots.