It's fairly simple. Everyone knows Hamas use tunnels but Israel justify bombing hospitals, schools and refugee camps with the justification that their are Hamas tunnels underneath. Now as someone who obviously cares about the Human species and since many innocent children and women are dying because of the bombing, since many people are dying because of this you would've thought that their would be some sort of incremental evidence to support their claims not just their word and some dodgy video claiming that this is a Hamas tunnel with a piece of paper with days of the week on it claiming to be terrorist names found.
You would also think that even if they were using tunnels underneath, a state with as much power as Israel would care more about other humans as to not bomb those places and find other means of taking care of Hamas without the damage to innocent civilians. Since, I'm sure if Hamas were hiding underneath a hospital in Israel their actions wouldn't be the same.