There is an interesting theory from @RWApodcast that the target of the strike may have been an Azov Battalion recruitment station *outside* the building.
This can't be proven definitively, but it seems plausible from this thread:
First, I expected the initial Russian missile barrage to be more effective at suppressing Ukrainian air defenses.
It's unclear whether the Russians were preserving precision munitions or whether MANPADs have filled the void from lost S-300s more effectively than projected.
Second, I expected the Russians to be more effective at disrupting Ukrainian comms with cyber attacks and electronic warfare.
In the past, they've had success making even NATO-provided radios useless. This capability has not been brought to bear the way I expected.