More thunderstorms headed across northern Alabama toward the city Saturday morning. "We're bracing for another round of whatever mother nature throws at us," said Lisa Janak of the state emergency management agency.
At least 27 people were hurt Friday night, though no injuries were believed to be life-threatening.
Mayor Shirley Franklin said the storm was "what we now know was a tornado." Weather service officials continued to say only that a "possible tornado" hit around 9:40 p.m. as a thunderstorm roared through with wind up to 60-mph wind.
All downtown events scheduled for Saturday were canceled, including the St. Patrick's Day parade.
The storm smashed hundreds of skyscraper windows, blew furniture and luggage out of hotel rooms, crumbled part of an apartment building and rattled a packed sports arena.
Streets around the Georgia Dome, Phillips Arena, the CNN Center and Centennial Olympic Park were littered with broken glass, downed power lines, crumbled bricks, insulation and the occasional office chair. Billboards collapsed onto parked cars.
CNN said its headquarters building suffered ceiling damage that allowed water to pour into the atrium, and windows were shattered in the CNN.com newsroom and the company's library. A water line inside the building broke, turning a staircase into a waterfall.
"It was crazy. There was a lot of windows breaking and stuff falling," said Terrence Evans, a valet who was about to park a car at the Omni Hotel when the storm twister hit.
A tornado warning had been issued for downtown a few minutes before the violent weather hit.
However, there was no announcement of the approaching storm for the 18,000 fans inside the Georgia Dome for the Southeastern Conference basketball tournament. The first sign was rumbling and the rippling of the fabric roof. Catwalks swayed and insulation rained down on players during overtime of the Mississippi State-Alabama game, sending fans fleeing toward the exits and the teams to their locker rooms.
"I thought it was a tornado or a terrorist attack," said Mississippi State guard Ben Hansbrough, whose team won 69-67 after an hourlong delay under a roof with at least two visible tears. A later game between Georgia and Kentucky was postponed. SEC officials said the tournament's remaining games would be played at Georgia Tech.
"Ironically, the guy behind me got a phone call saying there was a tornado warning," fan Lisa Lynn said. "And in two seconds, we heard the noise and things started to shake. It was creepy."
A half-mile away, the sign of the Phillips Arena parking garage was mangled but basketball fans inside the arena noticed little disruption during an NBA game between the Atlanta Hawks and Los Angeles Clippers.
Power was knocked out to about 19,000 customers.
A loft apartment building, built in an old cotton mill, had severe damage to one corner and appeared to have major roof damage. Fire officials said they were uncertain whether all the occupants had escaped, but property manager Darlys Walker told WSB-TV there was one minor injury.
Taylor Morris, 29, who lives near the lofts, said he and his girlfriend took shelter in the bathroom when the storm passed over in a matter of 15 to 20 seconds.
"The whole house was shaking," he said. "We didn't know what was going on."
Fire Capt. Bill May said a vacant building also collapsed, with no apparent injuries.
Grady Memorial Hospital, the city's large public hospital where many of the injured were taken, had broken windows but was operating as usual. Kendra Gerlach, spokeswoman for Atlanta Medical Center, said late Friday the hospital emergency department treated about five patients for minor injuries.
Buzz Weiss, spokesman for Georgia Emergency Management Agency, said state officials and the American Red Cross were setting up a shelter for displaced residents at a senior center.
In East Atlanta, downed trees, debris and power lines were strewn in the streets.
Melody and Brad Sorrells were home in their living room with their two children when the storm hit, and the huge pine in their front yard crash into their house.
"I saw it falling and we ran into the back bedrooms in the closet," Melody Sorrels said. "I feel sick."
According to the National Oceanic and Atmospheric Association, the most recent tornado to hit a major city's downtown was on Aug. 12, 2004, in Jacksonville, Fla. Downtown tornadoes have also struck Fort Worth, Texas; Salt Lake City; Little Rock, Ark.; and Nashville, Tenn., in the past decade.
If confirmed, the tornado would be the first on record in downtown Atlanta, said Smith, the meteorologist. The last tornado to strike inside the city was in 1975, and it hit the governor's mansion north of downtown, he said.