A large fire broke out about 4 a.m. Saturday at The Preserve At San Jose Condominiums.
By dawn, the fire was out, but the Jacksonville Fire and Rescue Department said at least 30 people were burned out of their homes.
Firefighters requested backup twice within 30 minutes as the flames spread through 12 units at the complex, making it a three-alarm fire.
Multiple fire trucks, JEA and the Jacksonville Sheriff's Office responded, and Old Kings Road was blocked for several hours.
The Red Cross was on scene assisting with the needs of the displaced residents. A spokesperson said the organization is currently helping 18 adults and two children.