The accident happened after a jet flyover when errant fireworks launched into the crowd at LaVell Edwards Stadium during the annual Fourth of July celebration.

Those who were injured and required medical attention have since been released from the hospital, according to Provo City Fire Marshal Lynn Schofield.

Information regarding the extent of those injuries were not released as the investigation is ongoing.

“It’s unfortunate this occurred, and we are thankful the injured are recovering,” Schofield said in a press release on Thursday.

Provo Fire & Rescue is still in the early stages of the investigation, which may take weeks before it is completed.

“We’re going to look at the folks who set up the show. We’re going to look at the device that failed,” Schofield told the Daily Herald when reached on Friday. “And those are two principal things we’re looking at, is it a problem with the device, or is there a problem with how it was set up, or is it a combination of the two.”

Kansas-based Stellar Fireworks was hired to produce the pyrotechnics show and has worked with Stadium of Fire for years. Schofield told KUTV last week that the company has a good reputation.

Regardless, the fire marshal stressed that the fireworks go through a rigorous inspection before show night, and they were deemed to be safe.

“We have a presence there [on the stadium’s field] multiple times during the week, and then the day of show we actually inspect every individual firework to make sure that it appears to be fused correctly and that it’s appropriately secured,” Schofield said.

America’s Freedom Festival at Provo, which organizes the annual event, echoed that in a statement released on social media hours after last Thursday’s malfunction.

“Safety is of the utmost importance to us. All pyrotechnics at Stadium of Fire are thoroughly checked before the show, and were rechecked after tonight’s incident,” a post on the festival’s official Facebook page reads.

While the current number of attendees hurt at the annual event stands at 18, the fire marshal isn’t ruling out the possibility that there may be others who were also impacted during the malfunction.

“I do suspect that there were more people that were impacted. That’s just the number of people that have stepped forward to this point,” Schofield told the Daily Herald.

Officials also stated in the updated release that investigators determined the initial count after compiling reports from first responders at the event and emails sent to ticket holders who may have witnessed what happened.

Anyone who was injured or struck by debris amid the fireworks error at the Stadium of Fire are urged to contact Lynn Schofield at firemarshal@provo.org.