While I was researching a completely unrelated topic, I discovered, much to my dismay, that one of my favorite stories about the Chazon Ish seems to be somewhat fictional. The story as I heard it, goes as follows:
During World War I, the Chafetz Chaim was stuck in Russia under Bolshevik control. A telegram arrived to the house of Rav Chaim Ozer Grodzinski on Erev Shabbos, requesting his assistance in obtaining the means to escape Russia, mentioning that it was a matter or פיקוח נפש. At the time, the Chazon Ish was in Rav Chaim Ozer's house, together with his brother-in-law, Rav Shmuel Greineman. Rav Chaim Ozer ordered Rav Greineman to travel to Warsaw immediately after Shabbos to arrange whatever was necessary. To this the Chazon Ish supposedly said "If it was written in the Mishna Berurah that a specific circumstance posed a danger to life we would certainly disregard Shabbos and take care of it - so now that the Mishna Berurah himself has told us that it is a matter of life and death, should we ignore his word [and wait until after Shabbos]." The story ends, that Rav Chaim Ozer agreed and that Rav Greineman left immediately for Warsaw that night.
This is how the story appears in R' Moshe Meir Yoshor's biography on the Chafetz Chaim (vol. 2, pg. 480)
The story is also quoted in R' Shlomo Cohen's "Pe'er Hador" (vol. 1 pg. 258) with slight variances (such as that the story took place on the night of Shavuos as opposed to Erev Shabbos). However in the footnote there he points to the introduction of "Chofetz Chaim Al HaTorah", which happens to be written by Rav Shmuel Greineman himself. Let's see how the story is presented by somebody who was there! (The story appears on page 12 of the edition available on Otzar Hachochma) According to his version, the story happened on the first night of Shavuos, and he prepared to travel to Warsaw that night, but didn't end up leaving that night because they found out that the minister he needed to meet wasn't in Warsaw at the time. According to this version, the Chazon Ish never appears in the entire episode!
