The Two Tablets of the Ten Commandments were broken: Taanit 26a-b, 28b
The bringing of the Daily Offering was suspended: Taanit 26b, 28b
Jerusalem was invaded, in the Destruction of the Second Temple: Taanit 26b, 28b
In the Destruction of the First Temple, Jerusalem was invaded on the 9th of Tammuz: Rosh HaShanah 18b; Taanit 28b
Apostimus [publically] burned the Torah: Taanit 26b, 28b
An idol was set up in the Inner Room of the Temple [by the Jews-Gittin 7a]: Taanit 26b, 28b-29a
In the Above case, 2 idols were set up, and one fell on the other and broke off its arm: Taanit 28b-29a
Laws of the 17th of Tammuz
Whether this fast is maintained during times of peace, and times when the Jews have their sovereignty: Rosh HaShanah 18b-19b
Bathing: Megillah 5b
