I've tried to go a different route than mere synonyms of sad. It is vicariously that you might feel some of the rapture experienced by those casualties, upon which whose blood you stand. Should those feelings endure long after your encounter, you might in some way, humbly count yourself among them.
rapture - a state of being carried away by overwhelming emotion –TFD
- the carrying of a person to another place or sphere of existence. –dictionary.com
While my toes twiddled in the sands of Normandy, I suddenly found myself enraptured by all the atrocities of war, and although it was a beautiful day, it was only with a shiver that my thoughts turned back towards the pampered existence that is my life.
vicariously, as per the title, the melancholy was felt.
- felt or enjoyed through imagined participation in the experience of others –dictionary.com
Having never been in the Service myself, I can only vicariously imagine the hell that is war.
In closing, I shall describe this person, who is so deeply humbled:
casualty - a person or thing badly affected by an event or situation. –Google
Men unhit by shrapnel or bullets were nevertheless casualties. –Stephen E. Ambrose