(CNN) -- What is it about an ice storm that worries people?
With forecasters predicting a winter storm of "historic proportions" that could bring anywhere from a quarter-inch to an inch of ice in portions of the Southeast, state and locals officials are taking no chances.
School has been canceled, government offices have closed and flights have been canceled ahead of the ice storm that is expected to coat portions of Alabama, Georgia, North Carolina and South Carolina.
Ice can wreak havoc on power grids.
During the Storm of 2000, as people in portions of the Southeast call it, an ice storm coated trees, causing them to snap and take out power lines. More than 500,000 homes were in the dark for days.
"When you're talking about that amount of ice we're looking at, it's catastrophic," Aaron Strickland, the head of emergency operations for Georgia Power, said Tuesday.
Slipping and sliding
People in places that get a lot of snow know this: You can drive on snow.
"Snow packs down. It's a little like brittle, it breaks up as you drive on it," said National Weather Service meteorologist Kurt Van Speybroeck said.
But ice, that's something different.
Atlanta got a taste of it a few weeks ago when less than three inches of a snow-sleet mix fell, melted a bit and then refroze, bringing the city to a virtual standstill.
"If you get even a 10th of an inch of ice on a road, it's like a skating rink," Van Speybroeck said.
Snow and ice also wreak havoc on roads, leaving in its wake potholes that can sometimes damage cars and trucks.
Take the ice storm that hit northern Texas in December. It left hundreds of potholes on roads, highways and interstates, the Texas Department of Transportation told CNN affiliate WFAA at the time.
Anecdotally, auto body shops in northern Texas also saw an increase in repairs during the same time period, with drivers requesting everything from front-end alignments to replacement mufflers.