The phrase "major calamity" refers to a very serious and devastating event or disaster. It usually suggests that something extremely unfortunate has occurred and has caused significant damage or harm. Full definition
He's also an experienced minister, who has been at several departments without major calamities. (bbc.com)
A consular SWAT force stands ready to race abroad in case of major calamity. (totalpolitics.com)
In his cabinet roles so far he has, as BBC political editor Laura Kuenssberg put it, avoided major calamity, although he faced questions as business secretary over Tata steel, and as communities secretary over the response to the Grenfell disaster. (bbc.com)