Wagner has been moving through the city by yards. The administration building is symbolic, but the Ukes still hold the western part of the city.
I think I would just blow up the administration building.
"holding" the western part of the city or "trapped" and unable to be supplied or relieved.
The two main roads out and into Bakhmut are compromised and any supplies are coming through some small roads and overland. As far as withdrawing without it becoming a route.... well that's another story.
Russians just doing what Russians do.... expend men, find the enemy, destroy every single building or cover with artillery or missiles and then rinse and repeat.
The Wagner group is probably combat ineffective and will need to be refilled with more convicts, mercenary misfits and whatever else they put in that group of storm-troopers.