ORLANDO, Fla. (WESH) — Fire rescue crews battled heavy flames at the Pet Alliance of Greater Orlando on Conroy Road in Orange County overnight.

The fire broke out around 10:27 p.m.

Officials with the Orange County Fire Rescue said when they arrived, the structure was 20% involved with flames through the roof of the building. The Pet Alliance works to find homes for around 10,000 pets a year.

Officials with the Pet Alliance said all dogs were saved during the fire, but believe they could have lost 20 to 30 cats. Officials said that at least 10 cats were pulled from the building.

According to officials, it appears the fire started at the front of the clinic, nearby where the cats are kept.

“If you run a shelter, this is literally your worst nightmare,” Stephen Bardy, the executive director of Pet Alliance said. “To see your building in fire and know that there are animals in there that you’re charged to care for and you can’t go in — I’m grateful that the firefighters put their lives at risk to help save as many as they could.”

Dogs and cats will be relocated to the Pet Alliance’s Sanford location.

Bardy added that many of the animals with Pet Alliance of Greater Orlando, around 50%, are currently with foster families.