A BBC correspondent who arrived in Istanbul some hours after the earthquake has described scenes of devastation.
In one suburb, he said, almost every other building had collapsed.
He saw rescuers working at the wreckage an apartment block, using cranes and heavy lifting gear to move concrete blocks.
Twenty-five people were known to be buried there, and at least one, a fourteen-year-old girl was thought to be alive under the rubble.
Our correspondent describes the rescue as a race against time, with people buried for many hours in stifling heat.
He says many of the buildings which collapsed were those put up during the recent economic boom, some shoddily constructed, as people tried to save time and money.
Our correspondent says the people living in those apartment blocks have paid a very high price for this economising.
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