Israelis mourned on Friday the loss of life when a joyous pilgrimage that drew tens of thousands of ultra-Orthodox Jews abruptly turned into a tragedy. And although the country was largely united in grief and shock, questions immediately arose about poor planning and possible negligence.

Even for a country accustomed to the trauma of wars and terrorist attacks, the deadly crush that killed 45 people during a mass religious celebration on Mount Meron in the northern Galilee region counted as one of the worst disasters in Israeli history.

There had been warnings for years that the site’s patchy infrastructure could not safely handle large crowds. The pilgrimage was also held despite warnings from Israeli health officials that it could become a Covid-19 superspreader event.

“We will conduct a thorough, serious and deep investigation to ensure such a disaster does not happen again,” Prime Minister Benjamin Netanyahu pledged on a visit to the site on Friday. He called for a national day of mourning on Sunday.