A Friday night fireworks performance at an Alabama festival was canceled after a technician had to be flown to UAB Hospital when they were injured by a shell that “unexpectedly detonated.”

“A firework shell unexpectedly detonated while being prepared; no power source was connected to the device, which is normally detonated via electric-match technology activated by computer,” the City of Jacksonville said on its Facebook page announcing that “tonight’s fireworks performance at Jax Fest has been canceled.”

The technician was flown by helicopter to UAB Hospital in stable condition, the city said.

No other people were injured in the incident.

The Jacksonville Fire Department described the incident as an “accidental discharge.”

“During the loading of fireworks there was an accidental discharge injuring the workers who were shooting the fireworks,” the department said. “Our thoughts and prayers are with him and his family.”

The company that was supposed to put on Friday night’s fireworks display will return at a later date to put on the show, the city said.

The city said it would put out more information on that date once it is known.

Residents may hear fireworks detonating during the day at the city’s public safety complex “while the site is safely decommissioned,” the city said.

Jax Fest is organized by the city’s parks department and is held at Jacksonville High School’s football stadium.