UPDATE: All security checkpoints are once again open at the Hartsfield-Jackson International Airport after an early morning terminal fire. But the airport said passengers are still waiting more than 30 minutes to get through security.
Two firefighters were hurt after slipping on water while battling the fire inside one of the airport terminals. They were treated with minor injuries.
Our NBC affiliate in Atlanta reports the fire started around 5 a.m. in the motor of an escalator leading from the airport train to Concourse T. An airport spokesperson said the concourse filled with smoke.
Passengers were evacuated from the terminal, but have been allowed to return.
The @Atlanta_Airport tweeted, "Heavy smoke on the train level near Conc T and it has since been contained. Passengers may experience longer security lines than normal."
Flights from Chattanooga to Atlanta are running as scheduled. The airport said all gates are openand flight operations are running normal.