There is a part right at the beginning after the major expolsion… where you come to a T junction… computers ahead of you but you need to turn right… If you head towards the computers and back again… there is some exposed pipe and the floor has lifted. … if you fall in there… no matter how much you jump you can not get out of the hole.
I would just reload to the last checkpoint or maybe if you push at a angle you can get out