Devil's Night is observed on October 30, 2021. Devil's Night, or Hell Night, is a name associated with October 30, the night before Halloween. It is related to the "Mischief night" practiced in other parts of the United States and the world, but is chiefly associated with the serious vandalism and arson seen in Detroit, Michigan from the 1970s to the 1990s, finally prompting the "Angel's Night" community response.
Devil's Nights dates from as early as the 1940s. Traditionally, city "youths" engaged in a night of criminal behavior, which usually consisted of acts of vandalism. These were almost exclusively acts of petty vandalism, causing little to no property damage. However, in the early 1970s, the vandalism escalated to more devastating acts, such as arson. This primarily took place in the inner city, but surrounding suburbs were often affected as well.
The crimes became more destructive in Detroit's inner-city neighborhoods, and included hundreds of acts of arson and vandalism every year. The destruction reached a peak in the mid- to late-1980s, with more than 800 fires set in 1984, and 500 to 800 fires in the three days and nights before Halloween in a typical year. (With material from: Wikipedia)