The Gemorah (Yevamos 62b) states that the students of Rabbi Akiva perished because they disrespected one another. This occurred in the period between Pesach and Shavuos. We therefore,, during those days, do not make weddings nor do we take haircuts (Shulchan Aruch Orach Chaim 493).
People sustain collective tragedies when attacked by enemies from without. The extent and duration of the suffering become minimized to a people whose strength is enhanced by their unity and shared common goals. Inner strife, greed, jealousy, vanity, hatred and resentment weakens a people and allows forces from without to "Divide and Conquer".
My Grandson, Yosef Binyamin pointed out that a profound example of this is found in the Biblical account of two occurrences our People experienced during their travels on their way from the Exodus from Egypt to the stand at Mount Sinai:
On the fifteenth day of the second month from their departure from Egypt. The entire assembly of Israel complained against Moshe and Aaron: "In the land of Egypt, We sat by the pot of meat, we ate bread to satiety, for you have taken us out to this wilderness to kill this entire congregation by famine" (Exodus 16). The People's request was granted. Quail descended and Manna rained down from heaven. From their complaint we see a expression of unity. Their concern was for a common cause, void of greed or resentment towards one another. We read of no negative consequences following this event.
They encamped in Refidim and there was no water for the People to drink. The People complained against Moshe and said: "Why have you brought us from Egypt to kill me and my children and my livestock through thirst? From this complaint we see selfishness, only concerned with Me, My and MY. The aftermath of this event was: Amalek came and battled against Israel in Refidim. (Exodus 17).
They journeyed from Refidim and encamped there before Mount Sinai.(Exodus 19:2). They did so as one person with one heart (see Rashi). Standing together in unity, the Divine Presence was revealed.
Divisiveness results in suffering for all. Unity results in blessings for all.