Investigators are trying to figure out what started the fire at the Atlantic Beach & Tennis Club in St. Augustine Beach.
"I live in a house right behind the club and I saw flames coming out of the building," owner Bill Brothers told First Coast News.
When his wife called 9-1-1, she learned firefighters were already battling the blaze in the 50-year-old building.
The club dates to the 1970’s and Brothers has owned it for more than 30 years. It had the only heated indoor pool in the area.
"It makes you sick to put 32 years into something and have it destroyed in a few hours. Doesn’t make you real happy," Brothers said.
Neighbors said they believe the structure was hit by lightning. But, officials have not confirmed that.