Atonement

The Talmud, which was compiled by the Jews in the 4th century, tells of how for centuries once a year on Yom Kippur (The Day of Atonement) a scarlet cord was tied to the horn of the scapegoat as the High Priest entered the Temple to make his annual sacrifice for the sins of the people. Every year this cord would miraculously turn white, indicating God’s acceptance of this sacrifice. Yet, according to the Talmud something strange happened one Yom Kippur: “Our Rabbis taught: During the last forty years before the destruction of the Temple the lot did not come up in the right hand; nor did the crimson-coloured strap become white.”
The Temple was destroyed in 70AD, forty years before would b 30AD. I wonder what single event occurred then, which did away with the need for further sacrifices- so much so, that any attempt at doing so would be rejected?!