At least 91 people, including 20 children, are feared killed by a huge tornado which tore through Oklahoma City suburbs, officials in the US state say.
Worst hit was Moore, south of the city, where neighbourhoods were flattened and schools destroyed by winds of up to 200mph (320km/h).
About 120 people are being treated in hospitals.
President Barack Obama has declared a major disaster in Oklahoma.
He also ordered federal authorities to join in the search efforts which are continuing throughout the night.
Monday's twister hit Moore, a suburb of about 55,000 people, at 14:56 (19:56 GMT) and remained on the ground for about 45 minutes.
The official death toll is 51, but local authorities say the figure is expected to rise as another 40 bodies have been found.
The Oklahoma chief medical examiner's office said at least 20 children were among the dead.
Plaza Towers Elementary school took a direct hit: the storm tore off the building's roof and knocked down walls.
"The school was flattened. The walls were pancaked in," Oklahoma's Lt Gov Todd Lamb told the BBC.
"There's still roughly two dozen children that are missing. There have been some bodies recovered from that school and it's absolutely horrific and devastating."
Another school - Briarwood Elementary - was also damaged, and teachers were later seen leading pupils out to safety.
Oklahoma Gov Mary Fallin said it was a "tragic" day.
More than 200 Oklahoma National Guardsmen as well as out-of-state personnel have been called in to assist the search-and-rescue effort.(BBC)
Photo courtesy- Reuters
Video by - ABC News
Comments - 14
Critic Roshan Tuesday, 21 May 2013 09:23 AM
One may think these are natural disasters. True, but most of natural disasters occur due to the good or bad behaviors of the present ruler of each country. This applies to the behavior of our ruler too.
Maha Rajanani Tuesday, 21 May 2013 01:08 PM
Why ? for whipping out ruthless terrorists from SL MAP.
Patriot Tuesday, 21 May 2013 01:11 PM
Even during this tragedy, all you can think of is yourself. You are a disgrace
Patriot Tuesday, 21 May 2013 01:12 PM
khan Tuesday, 21 May 2013 01:20 PM
Lesson for Athiests!
don Tuesday, 21 May 2013 02:07 PM
you harm others physically and natures turns back at you.
kumar Tuesday, 21 May 2013 02:10 PM
War criminals are still there!
kumar Tuesday, 21 May 2013 10:03 AM
Don't worry they will recover faster.
ANTON Tuesday, 21 May 2013 10:05 AM
LIVES OF DEAD PEOPLE INCLUDING CHILDREN, HEY, GET YOUR BRAIN TESTED.
Nihal Amarasekera Tuesday, 21 May 2013 08:16 AM
Nature of Nature is Good Bad and Ugly. We too are part of Nature.
mohamed asfar Tuesday, 21 May 2013 08:53 AM
my heartfelt condolences to all who lost their loved ones. my heart cries loud for those kids.
ind Tuesday, 21 May 2013 08:54 AM
Feel sorry for the victims. But this a repeated warnings for the desasters made to other countries by US.
ANTON Tuesday, 21 May 2013 09:10 AM
USA IS ONE OF THE HIGHEST DEVELOPED COUNTRIES IN THE WORLD, THEY MUST HAVE WELL DEVELOPED DISASTER MANAGEMENT SYSTEM.
Game Man Tuesday, 21 May 2013 09:14 AM
My Deepest sympathies for those who perished, and for those who survived please tell our Government to leave SL alone and worry about you.
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