I can't go back to the ruins (Shadow of the Tomb Raider)

The game went through, reached the goal of "Meet Jonah in ruins", did not notice that he said that he was down, went upstairs and jumped into the water. And now I can't go back there, I've tried by land, underwater, but there's no passage anywhere. Tried generally bypass, through the camp and further where the base was either at Trinity or else someone else, no way. How to continue playing?