Russia starts meteor clean-up

NEW: Divers find no trace of meteorite in a frozen lake near Chelyabinsk, state media report NEW: Witness says flash shone "like 10 suns," felt shock wave pass through his body More than 4,000 buildings, mostly apartment blocks, were damaged, reports say The meteor released a 500-kiloton blast, NASA officials say

Chelyabinsk, Russia (CNN) -- A day after a spectacular meteor blast shook Russia's Urals region, the clean-up operation got under way Saturday in the hard-hit Russian city of Chelyabinsk.

Although some buildings were unscathed when the sonic waves from the Friday morning explosion reverberated through the region, others lost some or most windows.

More than 1,000 people were injured, including more than 200 children, according to news reports. Many of them were hit by flying glass.

Most of those hurt were in the Chelyabinsk region; the majority of injuries are not thought to be serious.

.cnnArticleGalleryNav{border:1px solid #000;cursor:pointer;float:left;height:25px;text-align:center;width:25px} .cnnArticleGalleryNavOn{background-color:#C03;border:1px solid #000;float:left;height:25px;text-align:center;width:20px} .cnnArticleGalleryNavDisabled{background-color:#222;border:1px solid #000;color:#666;float:left;height:25px;text-align:center;width:25px} .cnnArticleExpandableTarget{background-color:#000;display:none;position:absolute} .cnnArticlePhotoContainer{height:122px;width:214px} .cnnArticleBoxImage{cursor:pointer;height:122px;padding-top:0;width:214px} .cnnArticleGalleryCaptionControl{background-color:#000;color:#FFF} .cnnArticleGalleryCaptionControlText{cursor:pointer;float:right;font-size:10px;padding:3px 10px 3px 3px} .cnnArticleGalleryPhotoContainer cite{background:none repeat scroll 0 0 #000;bottom:48px;color:#FFF;height:auto;left:420px;opacity:.7;position:absolute;width:200px;padding:10px} .cnnArticleGalleryClose{background-color:#fff;display:block;text-align:right} .cnnArticleGalleryCloseButton{cursor:pointer} .cnnArticleGalleryNavPrevNext span{background-color:#444;color:#CCC;cursor:pointer;float:left;height:23px;text-align:center;width:26px;padding:4px 0 0} .cnnArticleGalleryNavPrevNextDisabled span{background-color:#444;color:#666;float:left;height:23px;text-align:center;width:25px;padding:4px 0 0} .cnnVerticalGalleryPhoto{padding-right:68px;width:270px;margin:0 auto} .cnnGalleryContainer{float:left;clear:left;margin:0 0 20px;padding:0 0 0 10px} A large chunk of a meteor that exploded over Russia is found in a late on Friday, February 15. A meteor streaks through the sky before exploding with a flash and boom that shattered glass in buildings and left hundreds of people hurt. Workers repair a damaged power line near the wall of a local zinc plant. About 270 buildings were damaged -- mostly broken glass -- by shock waves caused by the blast, said Vladimir Stepanov of the National Center for Emergency Situations at the Russian Interior Ministry. The meteor leaves a white streak through the sky. The national space agency, Roscosmos, said scientists believed one meteoroid had entered the atmosphere, where it burned and disintegrated into fragments, according to RIA Novosti. The meteor's vapor trail passes over the city. A man removes shards of glass from the frame of a broken window. The meteor damaged windows at a sports hall. By noon Russia time more than 725 people had sought medical help. Meteor explodes over Russia Meteor explodes over Russia Meteor explodes over Russia Meteor explodes over Russia Meteor explodes over Russia Meteor explodes over Russia Meteor explodes over Russia Meteor explodes over Russia HIDE CAPTION << < 1 2 3 4 5 6 7 8 > >> Photos: Meteor explodes over Russia

Altogether more than 4,000 buildings, mostly apartment blocks, were damaged and 200,000 square kilometers (77,220 square miles) of glass were broken, the state-run RIA Novosti news agency cited the Chelyabinsk regional emergencies ministry as saying Saturday.

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Local officials have estimated the damage at more than 1 billion rubles (more than $33 million), RIA Novosti said.

With temperatures dipping well below freezing at night, the need to fix windows left gaping by the blast is urgent.

The city of Chelyabinsk was functioning normally Saturday as the repair work began.

Many believe it was a lucky escape as fragments of the meteor came raining down.

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West of the city, authorities sealed off a section of a frozen lake where it's believed a sizable meteorite crashed through the ice.

But a team of divers has found no trace of any meteorite in the lake, an emergencies ministry spokeswoman told Itar-Tass on Saturday.

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The meteor was a once-in-a-century event, NASA officials said, describing it as a "tiny asteroid."

The space agency revised its estimate of the meteor's size upward late Friday from 49 feet (15 meters) to 55 feet (17 meters), and its estimated mass from 7,000 tons to 10,000 tons.

The space agency also increased the estimated amount of energy released in the meteor's explosion from about 300 to nearly 500 kilotons. By comparison, the nuclear bomb the United States dropped on Hiroshima in 1945 released an estimated 15 kilotons of energy.

The whole event, from the meteor's atmospheric entry to its disintegration in the air above central Russia, took 32.5 seconds, NASA said.

About 20,000 emergency response workers were mobilized Friday, RIA Novosti reported.

Russian Emergencies Minister Vladimir Puchkov arrived in Chelyabinsk on Friday evening to take stock of the situation, Itar-Tass reported.

Hospitals, kindergartens and schools were among the buildings affected by the blast, said Vladimir Stepanov of the National Center for Emergency Situations at the Russian Interior Ministry.

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The national space agency, Roscosmos, said scientists believe one meteoroid entered the atmosphere, where it burned and disintegrated into fragments.

Amateur video footage showed a bright white streak moving rapidly across the sky before exploding with an even brighter flash and a deafening bang.

The explosion occurred about 9:20 a.m. local time, as many people were out and about.

Russians captured vivid images, many using dash cameras inside their vehicles.

Dash cameras are popular in Russia for several reasons, including possible disputes over traffic accidents and the corrupt reputations of police in many areas. Drivers install the cameras for their own protection and to document incidents they could be caught in.

Denis Kuznetsov, a 23-year-old historian from Chelyabinsk, told CNN via e-mail that he had heard and felt the shockwave despite being far from the center of the city.

At first there was a blinding flash lasting several seconds, which made him want to shut his eyes. The light shone "like 10 suns," he said. "This is no exaggeration."

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Then he experienced what felt like "a push," as a sound wave passed through his body. "For some seconds I simply stood," amid the sound of breaking glass, he said.

After calming his parents, Kuznetsov tried to call friends, but all cellphone coverage was down. The internet still worked, however, and he managed to reach a friend in the city center who told of emergency responders heading into the streets.

At first, confusion was widespread, Kuznetsov said, with many people believing the boom had to do with a satellite or plane. But within an hour or so, news broadcasts declared it was a meteorite.

"There was no panic. All behaved quietly," he said.

Schools and many offices closed. Kuznetsov monitored the news, as the reported number of victims "grew hour by hour," he said. "Thank God no one died."

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CNN iReporter Max Chuykov saw the meteor trail from the city of Yekaterinburg. He shared on Instagram that it was close to the ground.

Ekaterina Shlygina posted to CNN iReport and wrote on Instagram: "Upon Chelyabinsk a huge fireball has exploded. It wasn't an aircraft."

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Five regions of Russia, one of them Chelyabinsk, are thought to have been affected, Itar-Tass said. RIA Novosti cited emergencies ministry officials as saying three regions and Kazakhstan

NASA said on its website that the meteor was the largest reported since 1908, when the famous Tunguska event took place in remote Siberia.

In that incident, an asteroid entered the atmosphere and exploded, leveling about 80 million trees over an area of 820 square miles -- about two-thirds the size of Rhode Island -- but leaving no crater.

"We would expect an event of this magnitude to occur once every 100 years on average," said Paul Chodas of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in California.

"When you have a fireball of this size, we would expect a large number of meteorites to reach the surface, and in this case there were probably some large ones."

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In what astronomers said was an unrelated coincidence, a larger asteroid, called 2012 DA14, passed relatively close to Earth around 2:24 p.m. ET Friday.

Stargazers in Australia, Asia and Eastern Europe could see the asteroid with the aid of a telescope or binoculars, but it never got closer than 17,100 miles to the planet's surface.

The Russian meteor was about one-third the size of the asteroid. The two bodies were on very different trajectories, scientists said.