A massive storm system whipping up severe winds and spawning tornadoes cut a path across the U.S. South, killing at least seven people in Georgia and Alabama, where a twister damaged buildings and tossed cars in the streets of historic downtown Selma.

Authorities said a clearer picture of the extent of the damage and a search for additional victims would come Friday, when conditions were expected to clear. After the storm began easing Thursday night, tens of thousands of customers were without power across the two states.