This a cleaned up version of the script, but from what I can see the script looks fine.
One of the main reason the Tsunami wouldn’t count other parts is because those parts are anchored and you most likely are moving the Tsunami via tween or cframe, etc.
.Touched only runs when game physics touches the part, for example, the moving of a character would allow the event to fire. Since you are changing the Tsunami’s movement via. Cframe, tween, or another method that is not a physics way the part won’t fire a .Touched event on other parts.
if otherPart.Locked == false then
otherPart.Anchored = false
local scri = script.Parent.Del:Clone()
scri.Parent = otherPart
scri.Enabled = true
local ex = Instance.new("Explosion")
ex.Visible = false
ex.Parent = otherPart
ex.Position = otherPart.Position