If you listen closely, the bangs continue in the background for the whole clip. It sounds like the Marines are seeking cover under things (you hear one say 'quit pushing me from under the table' and another says 'please don't let it get any closer'). It could be RPG rounds, but it is more likely mortar rounds. They were used regularly by insurgents to attack Army camps at night in Iraq, and they can be quickly set up and moved. One good shot could kill most, if not all, these Marines. I definitely pray they made it out safely.

I did studio work for several years, playing guitar and bass, and I still play in a band. After saying that, I've got to say that was Awesome! I'd trade our guitarist for Jake! Nah, that wouldn't be cool, but I'd love to jam with him!