That happened to me on the last Turtle Bay mission too. Game crash as things got very intense toward the very end. I made a point of being a little farther away from my starmates toward the end, not being crowded by everyone. Having fewer missile explosions and lasers firing in close proximity around me helped (I think).
I ran into game crash issues a few times unfortunately. Quite often it seemed to be tied to high intensity moments with lots of missile explosions, flamers and lasers going off all around me at point blank range. I'd notice a frame-rate drop, and then a crash a second or two later. I've seen others complain about crashes like this on the Steam discussion boards and reviews for the game. So, it's a known issue and hopefully they'll address it in patches.
Unfortunately that's just the state of the game right now. I'd say a handful of times throughout the campaign, I experienced a nearly identical game crash. Since there are no checkpoints that means a mission restart.
Thankfully I never ran into a truly show-stopping crash or bug that made it impossible to complete the campaign. But I did have to restart a mission over a bug a couple of times (the mission just wouldn't progress, for example unable to enter the next area where you are obviously supposed to go), and restart the game after a crash a few times (I'm talking about 5-7 incidents total across about 25 hours of total play time). The Turtle Bay one was definitely the most frustrating one just because it was an obviously important moment in the game and I was feeling very hyped to play the mission once it got underway.
I still enjoyed the game overall but those experiences were definitely infuriating.