>>Even Russian soldiers, who obviously didn’t get the memo, were washed away.

My own suspicion is that the Russians mined the dam, planned to blow it up eventually - either as the Ukranian army started an assault on the left bank / started using the dam as a bridge for an assault or as they Russians were being forced out from the East. But it somehow was detonated before they intended it to - and so Russian soldiers were lost as well.

Just a theory - from someone with little direct military experience, and no armchair to be general from.