Some of the occasions where the blood didn't liquefy in the last few decades were: 1980, when a terrible earthquake hit South Italy; 1973, when Naples suffered an outbreak of cholera; 1939, when World War II broke out; 1940, when Italy joined the War; 1943, when Italy was occupied by the Nazis. And throughout the centuries the absence of the astonishing phenomenon has been precedent to religious persecutions, eruptions of the Mount Vesuvius, earthquakes, revolutions, wars and the deaths of kings,
Just saying
My very first thought.