I think this really depends on the company, the place I used to work for was a small family run company, there was a few insanely loyal employees who had been there for longer than I've been out of high school (and in one case longer than I've been alive), unfortunately for them when redundancies were announced my job was safer than theirs and somebody who had been with the company for about 30 years, would work on his holidays if requested, never had a sick day and knew the directors since they were kids, he was one of the first people to be made redundant, another who had been working for the company had been there for about 15 years was also up for redundancy.
It was a small family company, we all got on well, it was a close knit group and we'd all quite happily go to the pub together, but at the end of the day it's a business, they'll put the company first if it comes to it so you need to make sure you put yourself first.