.The deadliest US tornado season in 75 years has ripped babies from their mother's arms and transformed entire towns into apocalyptic scenes of destruction as the toll hit 523.
And it isn't over yet.
While warmer summer weather should hopefully reduce their intensity, the peak tornado season runs through July and twisters can strike at any time.
The damage is as unimaginable as it is unpredictable.
Funnel clouds drop out of a darkened sky, tossing cars and mobile homes up into the air, pulling huge trees out of the ground and tearing buildings apart.
The smaller ones touch down so briefly that one side of a street is flattened while the other is largely unscathed.
The bigger ones stay on the ground for miles, destroying everything for blocks on either side of their random path.
Two bad days accounted for nearly all the deaths: an outbreak of dozens of tornados that killed 314 people in five states on April 27 and a massive twister that killed 138 in Joplin, Missouri on May 22.
It was the deadliest day and the deadliest single tornado strike since modern record keeping began in 1950. 2011 now ranks as the fifth deadliest year in US tornado history.