If the missile attack on the Kramatorsk train station was deliberate, it is unequivocally an attack on civilians explicitly forbidden by the Geneva Conventions--i.e., a war crime which is completely unacceptable. That much the politicians have right.
Britain’s Defense Minister Ben Wallace denounced the attack as a war crime, and U.N. Secretary-General Antonio Guterres called it “completely unacceptable.”
The question we do not have answered is “who committed it?”
Ukraine blames Russia. Russia says it's a Ukrainian false flag. Both explanations are possible and plausible.
Both sides need to stand down and resolve their differences at the negotiating table. The time for a ceasefire is now.
Did you see photos with the serial number of that missile? It seems to belong to Ukraine based on other serial numbers, but I did not follow closely
The missile was of Russian design and presumably a model no longer used by Russia but is used by Ukraine. At least, that is Russia's claim.
Despite Russia claiming the "proof" is conclusive, it's nothing of the sort. On either side.
Both sides have less than stellar track records on human rights, both sides have formations known for brutality against civilians.
The one thing we can say with confidence is the train station was hit by a missile. Beyond that everything is speculation at this point.