?? Justify that claim please. Hundreds of Jewish communities wiped out during the Crusades?
That said, hardly worth getting too deep into on a thread about the disaster of Notre Dame.
https://www.jewishvirtuallibrary.org/the-crusades
https://www.chabad.org/library/article_cdo/aid/2617029/jewish/The-Bloody-Crusades.htm
“Although compared to later tragedies the loss of Jewish life was relatively small, with the main devastation occurring in but four Rhineland towns, the First Crusade has generally been regarded by Jews as a disaster of epic proportions. The period of counting the Omer, between Pesach and Shavuos, when the massacres occurred, became fixed in Jewish law as a time for mourning. A prayer commemorating the martyrs, Av HaRachamim, was added to the Sabbath morning services and is recited weekly, except on joyous occasions. Several Kinnos were composed remembering these events and became part of the Tisha B’Av service. There are several reasons why the First Crusade has been given such prominence, while other, seemingly far greater tragedies have not:
The four towns destroyed were major Torah centers of Ashkenazic Jewry. Although Jews resettled and rebuilt these communities, and Ashkenazic Torah centers flourished, the greatness of these cities martyred scholars was lost forever a theme that appears prominently in the Kinnos.
The Crusades set a dangerous precedent the rise of organized, popular, anti-Jewish uprisings. Although both the Pope and the local authorities were generally opposed to the Crusaders excesses in Germany, these leaders hostility to Jews caused them to remain apathetic to Jewish suffering, thus they generally did not intervene. After the First Crusade, instances of mob persecution occurred regularly. Therefore, the Crusades can be seen as the source for much of subsequent Christian persecution. In keeping with the traditional Jewish viewpoint, that the beginning of a tragedy is noted, the events of the Crusades are commemorated.”