This is what happened in Makiivka. It appears a large group of troops were inside enjoying Putin’s New Year’s speech. The were sitting above a basement filled with ammunition when hit by several HIMARS. The massive ammunition explosion started by a HIMAR brought down the whole building. Some 60 were reported dead, but digging out was by no means finished. One estimate I saw said about 200 dead and at least another 200 to 300 injured. There was a lot of military equipment next to the building which was also totally destroyed.
These LINKS may add clarity regarding the Ukraine precision strikes on Russia in this multi-front over two days:
1- 02 Jan: Clever. Ukrainians GET 2 BREAKTHROUGHS WITH 1 ATTACK | War in Ukraine Explained
https://www.youtube.com/watch?v=lubD4jIIYnk
2- They don’t even collect their dead | Military Mind | TVP World
https://www.youtube.com/watch?v=40wMWQOdVdg
3- Scores of Russian recruits killed in Ukrainian strike because troops were housed next to ammo dump
https://www.youtube.com/watch?v=YQBD4dHphws