It may be fraud. Fraud is the knowing misrepresentation of a material (or  important) fact, or the knowing omission of a material fact which a person is under a duty to disclose. A failure to disclose flooding of a building could easily be fraud. Failure to remediate, or correct, the situation after notice of it and an oppportunity (i.e. enough time) to take corrective action could be violation of the implied warranty of habitability, the obligation on landlords to ensure that leased premises are fit for their intended purpose. You therefore may have grounds to seek monetary compensation and/or terminate the lease without penalty; you should speak with a landlord-tenant attorney to discuss you options in greater detail. Good luck.