In a word, yes. It has happened. We had a bad flu go through my office in Jan-Feb 2019. I was in bed for a week, and relapsed two weeks later. My co-worker, an Army Lieutenant Colonel, died. He and his wife were both sick, he was so bad he went to the ER, there he went into cardiac arrest and then a coma, then died.
Influenza kills, a bad flu can kill a lot of people. Per capita, the 1918-20 Spanish Flu epidemic killed a lot more people than COVID.
Did you timewarp back to 1917 or something?