We all have heard warnings about the flu season. It seems to be following a typical pattern as occurs almost every decade—1947, 1957, 1968, 1977…But there is an outlier in the routine: the flu pandemic of 1918 which killed 55 million people around the world and is considered the deadliest health crisis in modern history and perhaps, ever.

1918 began in a regular manner. New Yorkers were focused on the Great War that raged overseas, food rationing and other mundane issues.