"What's scary is the unbelievable storm surge potentially in my own town, 15 feet of storm surge above ground level".
Here's a look at some of the destruction Irma left in her wake.
Tybee Island City Manager Shawn Gillen said waters were receding quickly, but numerous 3,000 residents' homes were flooded.
Federal Emergency Management Agency chief Brock Long said Hurricane Irma is going to pose challenges for first responders.
"I know for our entire state, especially the Keys, it's going to be a long road", governor Rick Scott said. One of the teams was preparing to fly into Key West, directly in the path of the storm. Authorities also struggled to clear the single highway connecting the string of islands to the mainland.
More than 1.2 million Georgia Power and Electric Membership Corp. customers were without power Tuesday morning.
Floodwaters are standing on parts of St. Simons Island, where many have also reported no electricity. Streets flooded, and flying objects turned into unsafe projectiles. A lot of the business recovery efforts there will depend on how quickly power can be restored.
Several major airports in Florida that halted passenger operations due to Irma began limited service on Tuesday, including Miami International, one of the busiest U.S. airports. In March, a couple in MI died of carbon monoxide poisoning while running a generator inside their enclosed garage attached to their house during widespread power outages from a windstorm.
During its march up Florida's west coast, Irma swamped homes, uprooted trees, flooded streets, snapped miles of power lines and toppled construction cranes. Hurricane Irma has proved to be incredibly unsafe. In its wake, buildings were torn apart, torrential rains flooded the streets and almost 7 million homes and businesses were left without power. As it exited on Saturday evening, maximum wind speeds were registered at 145 miles per hour, along with a risky storm surge. "It's going to be a massive cleanup", the mayor said.
Statewide, more than 5 million homes or businesses are without power, Bossert said.
A woman died when a tree fell on a vehicle in a private driveway, the Forsyth County Sheriff's Office said on its website.
"It's frightful, what we saw", Scott said. On its Twitter account, said it hopes "people who had their lives saved yesterday will take evacuation orders seriously in the future". The city urged voluntary evacuation of low-lying areas last Wednesday, before the storm hit.
Scott said the authorities had rescued more than 300 people in Jacksonville, a city of 880,000 which was hit by flooding on Monday. On Sunday, Irma claimed its first USA fatality - a man found dead in a pickup truck that had crashed into a tree in high winds in the town of Marathon, in the Keys. Both began resuming service Tuesday.
The National Weather Service in Atlanta issued a tropical storm watch for the area Monday and Tuesday. Another man was killed in Sandy Springs when a tree fell on his house.
"Gov. Nathan Deal has expanded the state of emergency to include all counties in Georgia", Georgia Public Broadcasting reported as Irma hit the state Monday.
Storm surge: The surge and tide at Fort Pulaski along the Savannah River brought waters to more than 12 feet, the second-highest on record - just below the surge level a year ago during Hurricane Matthew.
'Basically, Hurricane Irma is so strong and its pressure is so low, it's sucking water from its surroundings into the core of the storm. In Charleston, waves crashed over the city's Battery sea wall and filled downtown streets for blocks.