7. The 1918 Spanish Flu Pandemic
Though not a typical “natural disaster,” the Spanish flu pandemic of 1918 is among the deadliest global events in history. It spread rapidly across the world, infecting about one-third of the global population and causing an estimated 50 million deaths.
The pandemic severely impacted every continent, with mortality rates soaring in regions with inadequate medical care and sanitation. Its rapid spread and devastating death toll make it one of the most tragic health crises in modern history.