Anderson Cooper 360
But unfortunately, it was too late. >> reporter: eric de moura told cnn he received the letter in april, outlining how the concrete deterioration is accelerating. the roof situation got much worse. so extensive roof repairs had to be incorporated. the letter was helping homeowners to understand their share of the assessment, anywhere from $80,000 for a one-bedroom condo up to $336,000 for the potenthouse unit. the bigger question remains why the maintenance on the building had been deferred for so long and how and why no one foresaw the potential for collapse, almost unheard of in a modern u.s...