They've already been sold the whole suite of Western air defense systems in addition to the ex-Soviet gear they've already had. Patriot, HAWK, Gepard, etc.
Air sirens had already started so most people had moved down to the basements. Probably some people who couldn't, or who were caring for those that couldn't be moved were caught in the blast.
Brutal thing to do. At least they didn't go for a double-tap, just for the lulz.
Unfortunately the West can only provide air defense systems, not magic lasers that automatically shoot everything down every time. This is classic terrorism, where the defender has to be right every time, but the attacker only has to be right once.