258,000 houses destroyed by earthquake?

It appears that another terrible tragedy has taken place in Sichuan Province in the People's Republic of China. An earthquake has leveled 258,000 houses. So AP reports that Xinhua News Agency reported today.

But how did the Chinese news agency manage to come up with this large number just two days after the earthquake? Is there a chance it might be a bit high? A bit low? A bit too precise?

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