Preston Garvey, bitch, drowning (Fallout 4)

This Preston, to whom, damn it takes evil, you constantly need to report on the completion of the assignment and be sure to receive a new one, suddenly found himself at the bottom of the river and does not climb out, you bastard. If only he disappeared, you reptile, but then you have to go further. I tried to boot and replay, so it was pulled to the bottom there again. Steam license. Has anyone had something similar? How can I get him out of there?