A line of strong overnight thunderstorms - some producing tornados, frequent lightning, strong winds and large hail - moved through Northeast Georgia and Gov. Nathan Deal declared a state of emergency in some Georgia counties.
The National Weather Service issued a tornado warning for northern Hall County just before midnight. It expired at 12:45 a.m.
Radar indicated a severe thunderstorm capable of producing a tornado 17 miles southwest of Dahlonega and moving toward the northeast.
Dawson, Union, Towns and Habersham counties also were under a tornado warning earlier in the evening and the entire region was under a tornado watch into early today.
"We're going to see atmospheric conditions that indicated an outbreak of severe weather," said meteorologist Robert Garcia of the National Weather Service's Peachtree City office. "We're definitely concerned about the threat. Nothing is out of the possibility."
Officials who could be reached in Dawson, White and Habersham counties said there was no significant damage reported late Wednesday while they were under a tornado watch.
"We just got a tree down and power line. That's about it," said Dawson County Sheriff's Sgt. Tony Wooten.
State climatologist David Stooksbury said Wednesday a Particularly Dangerous Situation watch was in effect west of Georgia, which means the system likely woulld bring with it stronger tornadoes that most systems, possibly those in the F4 or F5 categories.
The weather service said 1 to 2 inches of rain was likely, with amounts topping 3 inches in and around the heaviest thunderstorms.
"You could really see some accumulating rain if you have thunderstorm after thunderstorm rolling over you," Garcia said. "Even after all the storms roll through, we're going to have to deal with the aftermath of all that rain draining off."
Garcia said residents along streams and creeks could see flooding.
Authorities late Wednesday said rescue crews were trying to free people trapped by wreckage from storms in north Georgia.
Georgia Emergency Management Agency spokeswoman Crystal Paulk-Buchanan said multiple people were trapped in structures that collapsed in the Ringgold area, about 100 miles northwest of Atlanta.
She said there have been at least 25 injuries in Dade County and four hurt in Floyd County.
She also said up to 25 people were taken to area hospitals after storms in Walker County, and five of them remained hospitalized Wednesday night.
Earlier in the day, severe storms turned deadly as they ripped through north Georgia downing trees, blowing out a window in a hospital and ripping part of the roof off an elementary school.
Authorities said they had reports of two deaths and dozens of injuries in the state's northwest corner after a storm slammed into the town of Trenton.
There were two deaths in Trenton and dozens of injuries, Dade County Coroner Johnny Ray Gray said he's been told. He said he didn't know the circumstances of how the people died.
Gray, reached by phone, was in Florida Wednesday night and was on his way back to Dade County to help with recovery efforts.
He said the south end of Trenton suffered heavy damage, including an apartment complex in the town about 125 miles northwest of Atlanta.
Multiple counties reported damage from possible tornadoes - and nearly 30,000 homes and businesses were without power - after the powerful storms charged through the state.
"The wind was blowing so hard it felt like my truck was going to blow over," motorist Dan Montgomery told the Rome News-Tribune. "People were panicking and turning and trying to get out of the way."
More than 150 homes were damaged by storms and 32 roads were closed Wednesday in Floyd County, the county emergency management agency reported.
The Georgia Emergency Management Agency said five nursing home patients in Dade County were moved to Chattanooga, Tenn., because of power outages. At least two school districts, Floyd and Dade counties, closed early for the day and students from a Dade County elementary and middle school damaged by the storms were sent home.
Superintendent Patty Priest said awnings were blown off at both schools, a greenhouse was damaged and cars were hit with debris from a nearby business. She said power was out at the county's three schools and students were being sent home.
"We're all safe," she said.
At Redmond Regional Medical Center in Rome, the storm knocked out the power, smashed a window and damaged the roof, said spokeswoman Lisa Brown. She said the hospital was running on generators but had not needed to reroute patients to other hospitals.
"We did get hit with some pretty strong winds," she said.
At Hartsfield-Jackson International airport - the world's busiest - flights scheduled to arrive in Atlanta Wednesday night were being held before they departed other cities due to high winds in the Atlanta area, federal aviation officials reported.
The weather system was expected to clear out by early Thursday.
Associated Press contributed to this report.