Rav Chisda and the Angel of Death
The Angel of Death cannot take Rav Chisda while he learns without pause, until a pillar of the beis midrash snaps and the noise startles him for a moment.
The Gemara quotes the fascinating story surrounding the death of Rav Chisda.
It was time for Rav Chisda to return his precious soul to his Creator. However, the Malach HaMaves could not find any time that Rav Chisda was not learning; his nonstop Torah study made him impervious to death. The agent of the Malach HaMaves sat on a pillar that supported the beis midrash where Rav Chisda was studying. The pillar snapped and the resultant noise startled Rav Chisda. He momentarily stopped learning and thus expired.