The air traffic control tower at Hartsfield-Jackson Atlanta International Airport was briefly evacuated on Friday after a fire alarm and reports of a gas smell. The incident occurred around 5 p.m., triggering a ground stop for all inbound flights until 6:15 p.m. The restriction was lifted approximately 45 minutes later, according to FOX 5 Atlanta.

A recording from LiveATC.net captured air traffic controllers instructing pilots during the evacuation. “Just keep taxiing V then F,” one controller said. “Were evacuating, so we are going ATC Zero, so you can call the ramp when you get close.” The term “ATC Zero” indicated the FAA facility ceased providing air traffic control services.

Controllers also informed pilots, “Everyone is going downstairs, so we’ll see what is happening here,” and “The frequency is going to be unmanned for a while… just hold tight.” A ground stop forced inbound flights to wait on the tarmac, with some aircraft landing under approach controller assistance.

An FAA official confirmed Atlanta Fire Rescue investigated the situation. FlightAware.com data showed delays rising from 280 to 360 during the incident, with nearly 600 cancellations by nightfall. Ten flights were canceled for the day.

Sources told FOX 5’s Tyler Fingert that some planes were diverted or placed in holding patterns. Radar images revealed multiple aircraft circling near the Georgia line. Firefighters later stated no gas was detected in the tower.