Looking at the marker for the soul who died in 1918, it is possible he had been gassed during the war and then was hit with the "Spanish Influenza". That combination was just about 100% deadly. Those who has survived the gassing had lungs so badly damaged the influenza killed them just about first off.

In many cases in my part of the country, you could see it wipe out almost entire communities. Oddly, doctors and nurses were among the first to go. Here in Maryland you could see where it had swept through convents like wildfire.

Why, yes, I do like old graveyards. You can learn so very much.