Halo 3: final mission glitch on warthog part - (no spoilers please)

I was playing the final mission of Halo 3: “Halo,” and I began to realize taht once I got the final warthog bit, a piece of my level was missing in the beginning of the falling tiles section. I compared it to a youtube video, and apparently there should be a structure of sorts to drive your warthog through, whereas I only have an empty space and a floating blue arrow. Am I doing something wrong or is this a bug with my game? If so, could any tell me how to fix this?

The final warthog drive area falls apart as time goes on. I take it you weren’t really sitting around ideally for a few minutes, so it’s probably a bug. Record it and submit it to support.