Influenza victims crowd into an emergency hospital near Fort Riley, Kansas in this 1918 file photo. The 1918 Spanish flu pandemic killed at least 20 million people worldwide.
Influenza victims crowd into an emergency hospital near Fort Riley, Kansas in this 1918 file photo. The 1918 Spanish flu pandemic killed at least 20 million people worldwide. National Museum of Health
Influenza victims crowd into an emergency hospital near Fort Riley, Kansas in this 1918 file photo. The 1918 Spanish flu pandemic killed at least 20 million people worldwide. National Museum of Health