At least 36 people have been killed after more than six dozen severe storms and tornadoes struck several states in the central US, authorities say.
Homes were flattened, schools and business smashed and vehicles and trees tossed aside by Friday's storms.
Authorities said one small town in Indiana was "gone" after the disaster.
The National Weather Service had received reports of at least 83 tornadoes in eight states by Friday evening, bringing the week's total to 133. Not all reports were confirmed, however.
The service issued "a particularly dangerous" tornado watch, which is set to continue into early Saturday in four states.
"Destructive tornadoes, large hail to 6.4 centimetres, thunderstorm wind gusts to 112km per hour and dangerous lightning are possible," it said.
The twisters have thus far affected one-tenth of the US population according to the weather service.
Authorities in Indiana say that at least 13 people have been killed in the latest storms there.
"Early reports indicate the heaviest damage is concentrated in southeastern Indiana including substantial damage in Henryville and Marysville in Clark County, and Pekin and New Pekin in Washington County," the state Joint Information Center said in a statement.
'A town destroyed'
Officials confirmed 13 deaths from the tornadoes in that state: four in Jefferson County, four in Washington County, three in Scott County and two in Ripley County.
The town of Marysville, near the border with Tennessee, was reported to be "gone", Major Chuck Adams, the sheriff's department spokesman, said.
Shelly Jones, a local official, said that houses were also missing near the unincorporated town of Chelsea in that state.
In Kentucky, at least 12 people were killed in tornado-related storms, the state department of public health said.
Four of those deaths were in Menifee County in the eastern half of the state, with a fifth in Kenton County, near
In southwestern Ohio, a 54-year-old man and a 64-year-old woman died in Clermont County.
Many of Friday's tornadoes were reported in Alabama's Madison county, with the weather service reporting "people trapped in rubble with injuries", houses destroyed, trees ripped from the ground and power lines down.
There was also damage to a maximum security prison but authorities say that none of the inmates escaped.
Elsewhere, in Indiana, officials in Clark County were scrambling to deal with widespread damage from the storm after roads were blocked by fallen trees and debris and power and phone lines were knocked out.
"I can't confirm any damage right there yet - we're just trying to concentrate on the more populated areas and we've been inundated with calls."
'Quite a bit of damage'
The high school in Henryville, a town almost entirely destroyed by the winds, suffered "quite a bit of damage" but luckily all the children were evacuated safely before the school's roof was ripped off. Only minor injuries - some cuts and scrapes - were reported, Adams told the AFP news agency.
After 11 high-voltage Tennessee Valley Authority transmission lines were knocked out in northern Alabama and southeastern Tennessee, about 57,000 customers of public power agencies in the TVA service area were without power on Friday evening in north Alabama, western Kentucky and southeast Tennessee, the power supplier said.
Six injuries were reported after 100 homes were damaged in Cleveland, Tennessee, the weather service said, and injuries were also reported in the town of New Pekin, Indiana.
This year, the tornados seem to have come slightly early, with the mild winter creating the right conditions for cold fronts to slam into warmer air.
This latest outbreak of twisters comes as people were still picking through rubble left behind by a series of tornadoes which struck six states on Tuesday and Wednesday, killing at least 13 people.
Peak tornado season in the southern states is usually March to May, and in the northern states late spring to early summer.
About 545 people were killed during last year's tornado season, the deadliest on record since 1936 and the third-worst since records have been kept, according to the national weather service.