HELP with giant spiders and Indiana Jones boulder

[Hekai]

I am stuck. I am playing Penumbra Overture and am in these tunnels with the giant spiders. I have to admit to even looking this up on a walkthrough. There is this section where there is acid on the floor that you roll a large rock into in order to cross. Just after that you turn a corner and see a bridge of three boards. When you try to cross a giant boulder comes and crushes you. Am I down the wrong tunnel? Is there a way to survive this?

Thanks.