One popular lecturer on line [I won't link because I prefer not to get personal] likes to say that Rav Hutner became Satmar later in life and blamed the Holocaust on the Zionists in his article in the Jewish Observer 1977.
The magic of the internet allowed me to access this seminal article on the Churban [he doesn't like the term "Shoah" and prefers "Churban"]. Here is a direct quote:
"It should be needless to say at this point that since the churban of European Jewry was a tochacha phenomenon, an enactment of the admonishment and rebuke which Klal Yisroel carries upon its shoulders as an integral part of being the Am Hanivchar - G-d's chosen ones - we have no right to interpret these events as any kind of specific punishment for specific sins. The tochacha is a built-in aspect of the character of Klal Yisroel until Moshiach comes and is visited upon Klal Yisroel at the Creator's will and for reasons known and comprehensible only to Him.