American authorities in several Midwestern states are searching for survivors and clearing damage after a string of powerful storms and tornadoes left at least 37 people dead.
The states of Indiana, Kentucky, Ohio, Georgia and Alabama were all hit by the intense winds which flattened homes, lifted rooftops and downed powerlines.
An unknown number of people are missing after communication lines were damaged.
A total of 90 tornadoes and 700 severe weather events were reported on Friday.
President Barack Obama has offered federal government help to the affected states.
''We are no match for Mother Nature at her worst,'' Indiana Governor Mitch Daniels told CNN on Saturday.
''But this is about as serious as we've seen in the years since I've been in this job, he said, in the town of Henryville.
The neighbouring town of Marysville was totally destroyed.
''Marysville is completely gone,'' said Chuck Adams of Clark County Sheriff's Department.
Jenn Helvering, 24, told the BBC she saw a storm cell cross the highway as she drove towards Henryville. She then came across wreckage, including an overturned tractor-trailer, alongside the road near the town.
Ms Helvering said she saw what seemed to be a funnel, when driving between two storm cells.
''The weather was terrible. I suddenly saw a tornado coming towards me, I could see it swirling, then I saw one behind me.
''I was stuck in between two tornadoes - my dad directed me while I was driving between the two tornadoes. It was truly terrifying.'' she said.
In Salem, Indiana, a toddler was found injured in a field after tornadoes passed through. She was taken to a children's hospital, where she was later identified.
Ohio Governor John Kasich says some of the worst damage in his state was in the town of Moscow. Many people there are homeless.
Thirteen people were killed on Wednesday in Missouri, Kansas, Illinois and Tennessee.