The addition of a partially open roof to the ohel after the burial of the Pnei Menachem solves the problem of tumas meis (impurity from the dead) for students who are kohanim, and who therefore cannot be in proximity to a gravesite. However, during the yahrzeits of the two Rebbes, thousands of people crowd into the ohel, effectively blocking the opening and spreading tumas meis from the graves into the yeshiva building. The administration now posts a sign warning kohanim to stay out of the yeshiva building on the day of a yahrzeit.Hall, Y. Kohanim in Today's World. Hamodia Magazine, 10 May 2006, p. 13.
