The observance of the day includes five prohibitions, most notable of which is a 25-hour fast. The Book of Lamentations, which mourns the destruction of Jerusalem is read in the synagogue, followed by the recitation of "kinnot", liturgical dirges that lament the loss of the Temples and Jerusalem. As the day has become associated with remembrance of other major calamities which have befallen the Jewish people, some "kinnot" also recall events such as the murder of the Ten Martyrs by the Romans, expulsions from England, Spain and elsewhere, massacres of numerous medieval Jewish communities during the Crusades, and the Holocaust.