in kharkiv. they are blaming each other for serious deconstruction. what do we know about what happened and what is being done i guess to save lives and property here? reporter: the exact cause of a substantial explosion that destroyed this hydroelectric power dam that holds up the dnipro river remains under investigation. of course ukrainians say russian pre-mined it, in other words set explosives on that dam. and that the ukrainian side of the dam had been regularly subjected to shelling. rather the ukrainian bank. so that had been under russian control. but nonetheless 80 settlements the government here saying are being affected as this vast amount of water is unleashed. huge amount of the water of course that has been built up over the winter months, melt water building up the size of the dnipro river now being unleashed downstream, likely to affect kherson or parts, districts of the city recappturd by ukraine last year. but most of the flooding is likely to be to the e