he says, "this is the report i wrote." >> alfonsi: bob kaible got out his phone and took a picture oforiginal report. it plainly said there was "structural damage" to the house. but this is the report the insurance company sent to kaible when they denied his claim. "not structurally damaged." they said the damage was "long term" meaning it existed before hurricane sandy. the kaibles' insurance company wright flood, the largest provider of flood insurance in the country, paid him just $79,000 of his $250,000 policy. >> kaible: we had a mortgage on the house. i've had estimates of $300,000 to $350,000 to rebuild the house. what am i gonna do? >> alfonsi: bob kaible's house was torn down after he sold it for a loss, and he believes it was because of a falsified engineering report. the photo kaible took was solid proof for many other sandy victims who were struggling with similar situations. how many houses do you see that are empty? >> kaible: on this block? probably half of them. >> alfonsi: the kaibles pleaded to a vice president at their insurance company and passed on their evidence.

bob kaible told sharyn alfonsi on "60 minutes" that his house in long beach, new york, was knocked off its foundation and condemned, but the insurance company's engineering report concluded there was no structural damage. >> i'm like, what do you mean there's no structural damage? the house is not what it was before. >> reporter: new york senator kristen gillibrand says she's heard similar stories from dozens of constituents. >> based on the documents i've seen, it looks like large-scale fraud. it's rigging the system against home owners to make sure insurance claims are not paid out. >> reporter: 40 phone calls later kaible was finally granted a re-inspection by the same engineer. i said, "george, how could you write a report like that?" he goes, "it's not my report." his report, they discovered, has been altered. engineer andrew braum, who works at a different company, says the same thing happened to him. 175 of your reports were doctored? >> correct. >> reporter: and the ones that weren't changed? >> the ones that weren't changed, interestingly, were ones where i recommended no repa