I bought a condo and got stuck with a $47K water bill

I purchased a condo last year and have inherited the buildings past debt-a $47K water bill. It did not show up in the title report because there was no lien placed on it at the time. They were making small payments toward it. Is there anything I can do? Sue the board? Sue my attorney? Am I truly entitled to this debt that I had no knowledge of? Any info would be helpful. Thanks.