During
World War II, Rabbi Grozovsky escaped
Europe and
the Holocaust with a group of his students and arrived on the west coast of the United States. He then journeyed to
New York City where he joined Rabbis
Aharon Kotler and
Avraham Kalmanowitz in leading the
Vaad Hatzalah's efforts to save Jews from the
Nazi Holocaust, including lobbying and fundraising. In the process, he also brought 110 members of the Kaminetz community to safety in America. Rabbi Grozovsky was extremely active in the
Agudath Israel of America organization. However, he preferred to work behind the scenes. His concern for the spiritual state of affairs in
Israel was well known. He read many magazine and newspaper articles about Israel and asked students to translate articles written in English. As a result of his knowledge, in May 1951 he organized a public demonstration protesting the unilateral action of the Israeli government in involuntarily sending religious refugee children to anti-religious
kibbutzim ("communes"). Rabbi Grozovsky was asked by Rabbi
Shraga Feivel Mendlowitz to head the
Yeshiva Torah Vodaas located in
Brooklyn, New York. There he earned a reputation for incisive analytical reasoning combined with vast
Talmudic knowledge and a humble and modest personality. Although he spent less than a year in this position, his influence on the Yeshiva belies the relatively short time he was associated with it. Reb Reuvain's schedule would have worn out many men who were physically stronger. He arrived at Beth Medrash Elyon in
Monsey, NY, every Thursday and remained awake all night preparing for the Friday Talmudic lecture. The same routine was followed the next night, when after his
Shabbos meal, he would prepare for his Sunday afternoon lecture. He then returned to Brooklyn on Monday to present the same lecture, modified for his different audience, on Tuesday. Six years before his death, he was struck by a car under suspicious circumstances [Rumour has it was the butcher meat mafia who arranged it, though there were other suspects]. He then suffered a
stroke which impaired his physical functioning . Nonetheless, the Rosh Yeshiva remained mentally alert and was able to study until his death in 1958. He was survived by his sons, Rabbi
Chaim Grozovsky and rabbi
Shamshon Grozovsky and his sons-in-law, Rabbis
Don Ungarischer (Rosh Yeshiva of
Beth Medrash Elyon) and
Levi Krupenia. ==Talmudic method==