Hello, So I read through the older post about this quest and its bug that doesn't allow you to blow up the tower and I tried something after the third time it froze on me: What I did was I did not talk to Tonn at the begin of the quest. Instead I ran through the instance killing all the undead and spiders in the way ( I ran around the Skalk there and killed them with the crew). After I cleared the first two towers I swam to the third making sure to stay clear of the Krait that come at the end of the quest. Then I proceeded to kill all the risen at the third tower and the Veteran last. After I ran back to Tonn and proceeded with the quest as normal with no problems aside from the defensive NPCs not moving in the tunnel until the task "clear the beach" popped up. I did notice that two of the Risen Plague Carriers suddenly vanished while fighting them and never reappeared, this might have something to do with the bug is one of the last Mobs is a Plague Carrier. Let me know if this helps anyone get through the quest.
