Transcript for Search for survivors continues after Mexico earthquake

There's also a search for survivors in Mexico after that massive earthquake. Powerful images like these showing rescuers forminging a human chain to free victims trapped this the rubble. Dozens saved but officials fear time is running out. Matt Gutman is on the scene with the latest. Reporter: Overnight that bizarre twist, rescuers learning that the girl an entire nation believed was calling out from the rubble of her school to rescuers apparently wasn't. She had been called Freida and the enindication minister told us there were possibly others. They heard her voice. Yes, the rescue teams heard her voice. Reporter: This press conference officials announced all children dead or alive have been accounted for. So how did the entire world come to believe that there were still children trapped in there? Information that was coming from the different teams so we were not certain about that. Now we're certain of the information that we are giving you. Reporter: Soon after as we set up for a shot, a piece of debris flying off the school's roof landing with a thud. Watch it. Watch it. Watch it. Suddenly commotion. The Marines force GLI evacuating the school making a final sweep of that pile was the L.A. County fire search and rescue team and its canines. You got to go inside just now with the dogs. Can you tell us what you saw? A lot of damage and destruction and we did our best to locate any type of survivors and unfortunately at this point we are not getting any type of live scent. Reporter: The L.A. County team of more than 60 pressed on to other locations overnight and across this city, desperate search and rescue efforts are still underway. Well over 50 have been rescued since that 7.1 magnitude earthquake on Tuesday. The death toll now rising to over 270. Now there is concern for those still trapped in the rubble. High pypothermia is a major concern. They've pulled people out of rubble seven to ten days after an earthquake, so still a sliver of hope, guys. All right, thank you, Matt. Hopefully that's still the case with this. That's coming up.

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