ATLANTA , Georgia ( CNN ) -- Atlanta 's Hartsfield-Jackson International Airport was back in operation late Thursday after lightning hit the control tower and severe storms knocked out power to the area . The control tower and three of the airport 's five runways were open , said Kathleen Bergen , a spokeswoman for the Federal Aviation Administration . All systems were running on emergency generator power . A ground stoppage was already in place for arriving or departing flights when lightning struck the tower at 8:45 p.m. , according to Bergen . People evacuated the tower and a smoky odor was investigated . At 9:10 p.m. , the all-clear was given and controllers returned to the tower , she said . But at 9:20 p.m. , the tower and parts of the airport were hit by a power outage . The outage affected all the airport 's runway lights , Bergen said . During the outage , planes headed to Atlanta from other airports were being held on the ground , Bergen said , and arrivals were circling or being diverted to other airports . Atlanta 's airport is one of the world 's busiest .
Lightning strikes a control tower at Hartsfield airport as people evacuated . Power outage follows lightning after severe storms roll through Atlanta area . Outage affects runway lights ; arriving planes diverted or told to circle .