Tisha B'Av is observed as a day of fasting and mourning. The fast begins at sunset and continues until nightfall the following day.
The book of Lamentations is traditionally read in the synagogue. The setting is often deliberately subdued. Worshipers may sit on the floor or on low seats as a sign of mourning.
Special poems of lament called kinot are also recited. They remember the destruction of the Temples and other tragedies in Jewish history.
Traditional observance includes refraining from eating and drinking. Other comforts are also avoided. These practices express grief rather than celebration.
Tisha B'Av comes at the end of a period of increasing mourning known as the Three Weeks. As the Ninth of Av approaches, traditional communities reduce joyful activities and prepare for the fast.