there is complete disorder, terrible devastation (in some place)
itfs as if an army had marched through (some place)
(some place) looks like a war zone
(it's) complete havoc (in some place)
(some place) looks as if (like) it's been hit (struck) by a tornado.
From the name of the Tartar khan Mamai, who led a devastating invasion of Russia in the 14th cent.
Большой русско-английский фразеологический словарь. — М.: ACT-ПРЕСС КНИГА. С.И. Лубенская. 2004.