It's good to see you out relaxing and enjoying yourself.
Likewise, good ( in a different way)to see fallen heroes make their last journey home. If they're from the WW2, have they been buried in Europe all this time?
I would think some were buried either naturally or by enemy forces. Some of these remains are found from looking in known battle areas or former POW camps. They even have dive teams that find remains in the sea from sunkin ships and submarines. Now sometimes the collection includes animal bones or human remains that aren't serviceman. It's not known for sure until it gets tested in the lab.