The air traffic control tower at Hartsfield-Jackson Atlanta International Airport was temporarily evacuated Friday night after a fire alarm and the smell of gas were reported, the Federal Aviation Administration said. During the evacuation, controllers declared “ATC Zero,” halting all tower air traffic services and prompting a ground stop for incoming flights. Some planes in the air were able to land with help from approach controllers, while takeoffs at the busy airport faced delays as staff dealt with the emergency, as per CNN.“A controller told a pilot, ‘Just keep taxiing V then F,’ according to a recording by LiveATC.net. ‘We’re evacuating, so we are going ATC Zero, so you can call the ramp when you get close.’”“ATC Zero” indicates that the FAA facility is not providing any air traffic control services. Another controller informed a pilot, “Everyone is going downstairs, so we’ll see what is happening here.”“The frequency is going to be unmanned for a while, because I have to evacuate as well,” the ground controller told pilots. “Just hold tight.”A ground stop was implemented for flights headed to the airport, causing delays in takeoffs. Some airborne flights managed to land with assistance from approach controllers, who normally guide planes to the airport before handing them off to the tower for landing.“We actually just landed uncontrolled,” a pilot from a flight originating in Greensboro, South Carolina, told other pilots. “We’re just trying to see what to do next.”“Nobody has taxied, landed or taken off other than you in the last 15 minutes,” another pilot added. Planes were grounded around 5 pm ET. The FAA stated that the ground stop was triggered by an alarm caused by a “strong” gas fume odor. First responders were present at the airport, FOX 5 Atlanta reported.Controllers resumed directing flights, and takeoffs and landings restarted just before 6 p.m. Air traffic controllers are deemed essential employees and are required to work during the govt shutdown, although they will not receive pay until it concludes. Staffing shortages have been reported at air traffic control facilities across the country this week as some controllers have stayed home. However, Atlanta was not listed as short-staffed in Friday evening’s operations plan.