Transcript for Maria leaves Puerto Rico flooded, without power

Hurricane MARIA also causing mass devastation. Emergency officials in Puerto Rico say the island has been destroyed. The storm knocking out power everywhere. More than two feet of rain sparking major concerns about flash flooding. Rob is on the ground there for us again this morning. Good morning, rob. Reporter: Good morning, robin. The winds have finally died down in San Juan but as you can see the damages has been done, fallen tree, utility poes, you name it. Debris all over they and not just the wind, the torrential rains just engulfing this city. Those this morning have finally come to an end. Overnight, the island of Puerto Rico submerged. After receiving more than 30 inches of rain and just 24 hours. Hurricane MARIA laying waste to this once tropical paradise. Roads now deserted. Signs that life here has come to a complete standstill. The catastrophic winds and downpours cutting off this island of 3.5 million people. The governor and National Guard going door to door this morning trying to rescue those whose homes are at risk. Intense flash floods pouring into small towns like this raging current sweeping through thetown of guaynabo. And a sea of darkness. Nightfall here in Puerto Rico where 100% of the island is off the power grid. Anybody with lights on has the luxury of a backup generator. The office of emergency management telling ABC news telecommunications have collapsed. 12,000 evacuees remain in shelters this morning. Outside dangerous dangling traffic lights threaten the safety of those below. In San Juan there's fallen debris all over the roads. The winds taking down these big old trees in old San Juan and balcony railings coming crashing down onto these cobblestone streets. This gas station almost unrecognizable. And the damage here to infrastructure is significant. 100% of the island without power. Communications extremely difficult. Survival mode will be toudh not just today but in the weeks going forward. Robin. Got to keep that in mind, rob, thank you.

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