How did the day of Ashura become the day of calamity...

How did the day of Ashura become the day of calamity, and sadness, and grief, and weeping apart from the in which Rasool-Allah -saww passed away, and the day in which Fatima -asws passed away, and the day in which Amir Al-Momineen -asws was killed, and the day in which Al-Hassan -asws was murdered by the poison\u2019.