A tiny summary of the fall of Jerusalem and the temple:
The siege lasted approximately 8 months and ended with the sacking of the city and the destruction of its famous Second Temple. The destruction of both the first and second temples is still mourned annually as the Jewish fast Tisha B’Av. The Arch of Titus, celebrating the Roman sack of Jerusalem and the Temple, still stands in Rome.
The emperor put pressure on the food and water supplies of the inhabitants by allowing pilgrims to enter the city to celebrate Passover, and then refusing to allow them back out. Food, water, and other provisions were dwindling inside the city, but small foraging parties managed to sneak supplies into the city, harrying Roman forces in the process.
The Christian Jews’ non-involvement in the revolt drove an obvious wedge between them and their traditional counterparts. Noting that after “70, Christians were not permitted in the synagogues anymore at all. The fall of Jerusalem, then, made the Christians even more distinct from the Jews and impelled the church to develop among the Gentiles.
excerpts from: https://en.wikipedia.org/wiki/Siege_of_Jerusalem_(70_CE)
Matthew 24 (NIV)
The Destruction of the Temple and Signs of the End Times
24:1 Jesus left the temple and was walking away when his disciples came up to him to call his attention to its buildings. 2 “Do you see all these things?” he asked. “Truly I tell you, not one stone here will be left on another; every one will be thrown down.”