Eleven people were injured — and two remain hospitalized — after a errant mortar exploded in the crowd during Vienna's annual Fourth of July celebration on Wednesday night at Waters Field, Fairfax County Fire and Rescue Department officials said.
The accident occurred at about 9:45 p.m. during the show's grand finale, said Dan Schmidt, a fire department spokesman.
A Chinese-made, multi-shot "cake box" firework, which contained 25 tubes with 3-inch-diameter mortars, "failed catastrophically" and sent at least one mortar flying into the crowd, officials said.
The mortar exploded near the playground area at nearby Vienna Elementary School. Battalion Chief Keith Johnson was 75 feet away when the firework landed and was the first responder on the scene.
Johnson described what he encountered as "chaos, people screaming, running, crying."
Two of the victims suffered potentially life-threatening injuries, Schmidt said. Six injured people were taken by ground transportation to Inova Fairfax Hospital. One of these patients, a child, since has been transferred to Children's Hospital, officials said.
One wounded person was flown by helicopter to Washington Hospital Burn Center in Washington, D.C. As of Thursday afternoon, this person remained hospitalized.
Four other bystanders were treated at the scene for minor injuries, fire officials said.
Five of the seven victims who required hospitalization were children, authorities said. Fire officials said they could not disclose further details about the victims' identities or conditions.
Thirty emergency personnel were on the scene when the accident occurred and responded one minute later, Johnson said.
Two Emergency Medical Service task forces tended to the victims, Johnson said. Fire officials did not clear the scene until 3 a.m. on July 5, he said.
Fairfax County follows National Fire Protection Association standards, which require 70 feet of crowd buffer space for every inch in diameter of a show's largest firework. Vienna's program used up to 4-inch-diameter shells, so the minimum buffer zone was 280 feet.
Bystanders injured by the mortar were located well-distant of this safety zone, Johnson said. The incident was "totally accidental in nature," he said.
The fireworks display was put on by Schaefer Pyrotechnics Inc. of Ronks, Pa., which has performed this service for the town for 10 to 15 years, said Town of Vienna spokesman Marie Kisner. Town officials signed a five-year contract with the company in 2004, she said.
Officials from Schaefer Pyrotechnics did not return a call asking for comment. Three Fairfax County fire inspectors approved the company's site plan and on-site fireworks setup, Schmidt said.
"All safety precautions were met by the company," he said.
The fireworks operator who touched off the errant mortar acted according to established procedures, fire officials said. The multi-shot container failed shortly after ignition and breached between 600 and 800 pounds of sandbags set up as protection around the 2-by-2-foot box, said Fire Inspector Ron Sheffield.
Twelve fireworks shows were performed in Fairfax County on July 4 and similar incidents occurred at four of those locations, none of which resulted in injuries, fire officials said.
Schaefer Pyrotechnics was the fireworks company involved in all of those other cases, which happened at Langley High School in McLean, Westwood Country Club in Vienna, International Town and Country Club in Fairfax and Springfield Golf and Country Club, officials said.
Deputy Fire Chief David McKernan said the company has proven reliable in the past.
"We haven't had a problem with them or we wouldn't permit them," he said.