The evacuation of nearly 88,000 people began when a wildfire swept through Fort McMurray, Alberta, Canada, and burned for another 14 months, becoming the costliest disaster in Canadian history.
Argentine president Juan Perón expelled Montoneros from a demonstration in the Plaza de Mayo in Buenos Aires, forcing the group to become a clandestine organization.
Sicilian separatist Salvatore Giuliano and his gang fired into a crowd of May Day marchers near Piana degli Albanesi, Sicily, killing 11 and wounding 33.
Second World War: British and Indian forces conducted a successful airborne assault on a Japanese artillery battery during the advance to liberate Rangoon, Burma.