Fire officials say the blaze was reported at a vacant building once used as a training facility for firefighters. There were no immediate reports of any injuries.
Hartsfield-Jackson, which is located south of downtown Atlanta, is the world's busiest airport.
The Atlanta Journal-Constitution reports the fire was burning as early as 5:30 am., and that firefighters were taking a defensive posture in battling the blaze. It was unclear late Thursday morning if the fire had been brought under control.
Written by Associated Press