are always the same we have seen it all before, destroyed buildings and shootings and explosions and they re always looking for someone to blame. our russia editor, steve rosenberg, has been to the scene of the attack and a warning, you may find some of the details in his report, upsetting. it was hard to believe that only yesterday this was a concert hall. in what was left of crocus city, the full horror of what had happened became clear. the attackers had torched the building. a rock concert became an inferno. shooting but first, the gunmen had opened fire. to kill as many of the audience as possible. in one constant stream of bullets. russia says the four gunmen who did this have been arrested, and claims they planned to cross into ukraine. kyiv denies any connection to the attack. it s islamic state that s claimed responsibility. president putin promised vengeance. translation: all the perpetrators and organisers of this crime and those who ordered it will be justly a