Go check it out

You check a fix on the location the auto response signal came from and you and the surviving crew head out that way. You have to raft through a long expanse of steep crumbling red rocks rising like spears from the water. At one point while going down a narrow passage between two cliffs a boulder falls onto the raft containing Jethers. The raft disappears under fifteen tons of stone. That's it for Jethers then....