3 March 2012
Last updated at 14:34
States across the US South and Midwest have been hit by thunderstorms and tornadoes, with reports of multiple people killed and widespread damage.
By late Friday, tornado warnings were in effect in Alabama, Kentucky, Tennessee and Indiana, with parts of West Virginia and Florida also under advisory.
Scientists said some of the tornadoes packed top wind speeds of 170mph (270km/h) and were up to 200 yards (182m) in width. In Alabama, the winds split power poles into two.
"Extreme damage" in Henryville, Indiana, included the destruction of a high school, several overturned trucks and wide-scale destruction across residential areas.
From the sky, the scale of the damage is clear. A school bus was blown into a restaurant and a roof was lifted from a school in the Indiana town.
Several areas in Kentucky and Tennessee saw multiple rounds of dangerous storms on Friday.
Earlier in the morning a line of storms took its toll in Alabama, with at least five people taken to hospital in the Huntsville area.
Cars were blown off the road, power lines came down and homes were battered by the severe conditions.
Tornado season begins in March, but meteorologists have said that it is not uncommon to see twisters earlier in the year.
Clean-up operations are already under way. But rebuilding businesses will take longer. The welding firm of Steve Burnett - seen here with his wife Rhonda and Amos Calloway - was destroyed by Indiana's extreme winds.
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