A set of fireworks malfunctioned at a Colorado fireworks show Friday night, sending fireworks into a crowd of people and injuring nine spectators, fire officials said.

About 17 minutes into the "Salute to the USA Fireworks Show" in Avon, a shell in the middle of a rack of fireworks exploded in its tube instead of shooting into the air, the town confirmed to NBC News.

The explosion then caused the rest of the shells to tip over, sending "two or three" fireworks over Nottingham Lake and toward the tightly-packed spectators.

"There was not a lot of room in between groups of people, so when it happened no one could really get up and run," a spectator, Jane Imber, told NBC News. "It was so scary."

Thankfully no serious injuries when fireworks exploded in brilliant green in the crowd to our left in Avon, CO pic.twitter.com/l7VpK6hRMu — Chris Vashus (@CLVashus) July 4, 2015

The nine injured people suffered "minor abrasion burns" at the scene, and were quickly helped by police and medical teams who were at the event, the town said in a statement.

"This is Avon's 29th year of presenting one of the most spectacular fireworks displays in Colorado, and we have never had any failure in the production," said Deputy Chief Greg Daly, who oversaw the response. "It is wonderful news that the injuries were very minor."

The town also said the "safety distance" between the crowds and the fireworks, as well as the firework crew's rapid shutdown of the show, likely prevented any further harm.