HOLLYWOOD, Fla. (AP) — Fire suppression equipment exploded in a South Florida casino Monday morning as crews performed maintenance work, causing six people to be hospitalized and 20 others to be treated at the scene, officials said.

None of the injuries at Seminole Classic Casino Hollywood were life-threatening, Hollywood Fire Rescue told news outlets.

Contract workers were performing routine service on the building’s fire suppression system when a gas canister ruptured, Seminole Tribe spokesperson Gary Bitner said. The explosion occurred on the second floor in an area not accessible to the public, but debris flew across the casino’s main floor, fire officials said.

Bitner estimated about 100 employees and guests had been in the building.

Hollywood and Seminole officials were investigating the cause of the explosion. They didn’t say when the casino might reopen.

The building is located about a half-mile south of the much newer and larger Seminole Hard Rock Hotel & Casino, which features a landmark guitar-shaped building.