Drinking Wine in the Mourner's House: Pesachim 110a, Ketuvot 8b
Shutting down the Study Hall of a Legal Decisor who dies: Moed Katan 22b
Shutting down all of the Study Halls, and changing seats in the Synagogue, for a Chief Justice who dies: Moed Katan 22b
Shutting down the Study Halls, and praying only as individuals except for the reading of the Torah, for the death of a Leader ["Nasi"] of the Jews: Moed Katan 22b-23a