>> reporter: not much. mexico city was built on a former lake bed. the aztecs founded the city on a lake and used to get around in canoes. when the spanish came in, they put the city on top of the lake bed and that's one reason the yaiks so harrowing. the soft soil can amplify the earthquake waves and make it feel like bowl of jello. but only parts of the city are on the lake bed. other parts are on the bed rock. and those fared very well. the parts on the lake bed were where the buildings collapsed and where there's been trouble. power has been restored to most of the city. in some areas it hasn't because they don't want to hamper the efforts in case there are fallen cables. >> we're talking about the victims but there are also heroes. reporting mexico's moles.