Today, practicing Jews mark the minor holiday of Lag BaOmer, the 33rd day[*] of the counting of the Omer [=the period between Passover and Shavuot]. According to legend,many students of Rabbi Akiva died in a plague that ended on Lag Ba-Omer. The surviving remnant included Rashbi (Rabbi Shimon bar Yochai), one of the pre-eminent scholars of his generation and later the attributed author of the Zohar [“radiance”, a mystical commentary on the Torah that became the foundational work of the kabbala school of Jewish mysticism]. [**]
Lag Ba-Omer is marked with bonfires, in which often marshmallows, (kosher) hot dogs,… are roasted.
In addition, 100,000s of fervently religious Jews make a pilgrimage on that day to the tomb of Rashbi, in the Upper Galilee village of Meron, not far from Tzfat/Safed. The site is always jam-packed on that day, and a number of people in the know said it was disaster waiting to happen.
Last year, there had been a cap of 1,000 visitors on account of COVID: this time around, the cap was raised to 10,000, but approximately ten times that number showed up.
A fairly detailed Wikipedia page in English is already up. It is not the first time in recent memory tragedy has struck on the day — a few years ago, unseasonally hot and dry weather led to bonfires becoming wildfires, killing several — but with 45 dead and 150 wounded, this is the largest civilian disaster in history. Full coverage by clicking on the banner below:

Apparently people stumbled in the narrow passage at the exit of the tomb.
Health Ministry director-general Prof. Ḥezy Levy has clarified that, while 17 of the 150 injured people are hospitalized, none are in critical condition.
The tragedy, he added, could have been prevented: “In hindsight we can say that the writing was on the wall. The events at Mount Meron have been going on for years. There are those who claim that this year there were less people because they tried, which did not happen, to go according to the coronavirus plan.”
“When there is a tragedy we always say that ‘the writing was on the wall,’ but we need to investigate how they prepared from a safety perspective, and the security of the worshipers and those celebrating on Mount Meron. These things will be investigated when the time comes by the authorities. I suggest that we do this in an authorized fashion, after we comfort the families and bury the corpses, to my sorrow, and treat the wounded.”
Speedy healing to the wounded, and condolences to the bereaved. Official condolences are flying in from across the world (even from Turkey!), and PM Netanyahu has declared a day of national mourning.
[*] in gematria (Hebrew numerology), lamed=30, gimel=3, hence lag=33. Numerology enthusiasts may note this is 18 Iyar on the Hebrew calendar, with 18 of course being ḥai (חי), i.e., “alive”.
This year, it happens to coincide with April 30, which since my teens I have been marking as Yom Mavet ha-Mamzer [the anniversary of the death of the b*stard], in honor of the Jewish joke where Hitler [y”sh] visits a soothsayer and is told that he will die on a Jewish holiday. “Which one?” “Any day on which you die will be a Jewish holiday.”
[**] The Zohar is a classic example of a “pseudoepigraphic” work, i.e., one where its author(s)tried to enhance its prestige by ascribed authorship to a famous person of the past. In this case, a Spanish rabbi named Moses de León (a.k.a. Moshe ben Shem-tov di Li’on, a. 1240-1305 CE) either wrote or compiled the work, and ascribed authorship to Rashbi.
A musical example of a pseudoepigraphic work is the famous Adagio “by” Albinoni, composed by musicologist and Albinoni biographer Remo Giazotto (1910-1998 CE). Giazotto’s son Adalberto is a fairly famous physicist who was instrumental in the first experimental detection of gravitational waves.