Fill them with flammable gas and ignite it. Then flood them.
I don’t know the absolute best and effective manner for destroying them, but I’m betting the IDF may have a plan ... :-) ...
“Fill them with flammable gas and ignite it. Then flood them.”
Israel knows how to destroy the tunnels. But first they must find them and I believe Gaza is 20 miles long.
Plus, once they do identify the tunnels, they will have to destroy them without damaging the security wall/fence.
Reminds me of WWII when our troops used flame throwers to persuade Japs (that's what they were in those days) our of the myriad tunnels on those islands. Similar tactics by the Irraelis against Hamas would be sure to bring cries of "Oh the humanity!" from the left and the press (excuse the redundancy), but in total war anything goes.