Even a couple of delayed fab500 gone deep would not collapse a building of that size so neatly. Would be interesting to know if they are destroying them before the arrival of russian troops or when they are entering it. It clear the view to see the advance of them and deny using it to shot at the next from the higher floor tho.The video says that this was a Ukrainian stronghold that was destroyed by a Russian missile strike. However it looks to me the Ukrainians blew up the buildings themselves to prevent them from capture. As these buildings are in the 'citadel' area this implies that the Russians may have already breached the defensive line.