what happened to all the background guys?

ok well i was wondering how did everybody die? the crew was made up of 17 people (i am not sure david was counted in that number, but i am going to assume he was) so there were only 2 survivors that means 15 people died, but when? ok so milburn died first so thats 14, then Holloway thats 13, the cargo bay scene is the tricky part so i will talk about that later, weyland was hiding so he was not part of the 17, the other lady and the security guy are killed by the enginere so thats 11, fifeld gets run over and burned thats 10, the captan and his 2 pilots die so thats 7, and then vickers gets crushed that's 6. now in the cargo bay fifeld was killing a lot of people, but it couldn't have been 6 because there was the guy driving the car and running him over, and 2 guys standing outside of weylands room when he was getting ready. i am not sure how many people fifeld killed, but that's still 3 people still alive at the least, so wtf happened to them? were they on the ship when it crashed? why didn't they get off with vickers? what happened to them? WHAAAAAAAAAT?!?!?!?!?!? if they did just die in the crash then the captain is an asshole for not warning them lol