During World War II Zhytomyr and the surrounding territory came for three years under Nazi German occupation and was Heinrich Himmler's Ukrainian headquarters. The Nazi regime in what they called the "Zhytomyr General District" became what historian Wendy Lower describes as "a laboratory for… Himmler's resettlement activists… the elimination of the Jews and German colonization of the East—transformed the landscape and devastated the population to an extent that was not experienced in other parts of Nazi-occupied Europe besides Poland. [While]… [u]ltimately, the exigencies of the war effort and mounting partisan warfare behind the lines prevented Nazi leaders from fully developing and realizing their colonial aims in Ukraine… In addition to the immediate destruction of all Jewish communities, Himmler insisted that the Ukrainian civilian population be brought to a 'minimum.'"
I think Zhitomir was in the old Tsarist “Pale of Settlement” where all the Russian Jews had to live. Naturally, Himmler would work his ravages there.
I would think that the areas around Leningrad, the Rzhev Salient-Smolensk, and of course Kharkov-Kursk-Orel saw the heaviest devastation, as heavy and prolonged fighting took place there.