On the evening of March 22, footage began to roll out from in and outside Crocus City Hall, a concert venue near Moscow, of an attack quickly claimed by the Islamic State, or IS. Four men, three of them armed with assault rifles and a fourth with incendiary devices, attacked an auditorium filled with spectators awaiting a sold-out concert. The attack left at least 140 people dead, including three children, and 150 more injured. The attackers reportedly fled as the fires set inside spread and the roof of the building collapsed in a burning mass of debris. “Islamic State fighters attacked a larg…