j happening now officials say at any moment the building damaged by the horrible earthquake in mexico city could collapse. v survivors believed to be in the rubble. >> holding back rescue crews, the mexican president says as many as ten of the collapsed buildings could still have people alive underneath. cnn correspondent rosa flores live in mexico city for the latest. what are you seeing? >> well, i can't begin to describe the emotions, john and poppy, that are being felt here on the ground. there are families here right behind us, just feet from here, who have been here since tuesday, more than 60 hours of agony waiting to see if their loved ones will emerge from the rubble. i want you to look over my shoulder because this is the building that officials here believe could collapse at any moment. that, of course, news that these families do not want to hear at