A: The main cause of rapid population growth is when there are more births than there are deaths, which is referred to as a natural increase. Other causes of ... Full Answer >
Spanish flu (1918-1919). The influenza pandemic of 1918-1919 killed more people than the World War I, at somewhere between 20 and 40 million people. It has been cited as the most devastating epidemic in recorded world history. Known as Spanish Flu or La Grippe the influenza of 1918-1920 was a global disaster.
The regular flu kills about 35,000 people every year, mostly infants and the elderly. I think pneumonia is the main complication that causes deaths. Those at most risk have co-morbidities. If someone has COPD their respiratory function is already compromised so it doesn't take much more to push them over the edge.