The Israelis were and are prosecuting a war they did not start and did not seek. In wars, people get killed and maimed. Combatants die, to be sure, but also civilians who are in harm's way.
If war comes to your neighborhood in Gaza, you're likely to be in harm's way. Today's episode in the Gaza/Hamas war is an Israeli bombing in which seven NGO aid workers were killed.
It wasn't their neighborhood, they either came to or remained in a war zone voluntarily, to do their job. Getting killed was a risk they chose to take, and they lost their bet with fate.
You may view them as heroes, fools, or something else - it's your choice. I have chosen not to view them as martyrs.