At least 23 people have been killed as tornadoes struck Lee County in eastern Alabama, authorities say, the BBC reports.
County Sheriff Jay Jones said there had been "catastrophic" damage and there were fears more bodies would be found. The number of injured is not yet known.
Rescue efforts have been halted until dawn due to the danger of searching in the dark.
The most devastating tornado struck the area around Beauregard, carving a path at least 0.8km wide.
The National Weather Service (NWS) classified it as at least an EF-3 - meaning winds of up to 266km/h.
It warned people to "stay out of damaged areas so first responders could do their job."