TAMPA, Fla. — Five dogs died in a mobile home fire the day before a dog show was to begin in Florida, authorities said.

The fire was first reported Tuesday afternoon at the Florida State Fairgrounds in Tampa, said Rob Herrin, spokesman for the Hillsborough County Fire Department.

The American Kennel Club All-Breed Dog Show was scheduled to begin Wednesday at the fairgrounds and run through the weekend.

Passersby reported seeing smoke coming from the RV’s vents and then tried to get into the car but were unable to due to the flames and smoke, Herrin said.

After firefighters extinguished the fire, the RV’s owners told investigators that five boxers had been inside the vehicle.

No humans were injured, authorities said.

Investigators believe the fire was an accident but are still looking for a specific cause, Herrin said.