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