It would be worthwhile to know whether these people were at all prepared to deal with bears. My guess is they were not armed. If not, they never had a chance, as it's clear the bear was not afraid of people and apparently saw these campers as a food source.
Minimum weapon for this situation would be a .44 Magnum, this combined with some training to hit critical points should the bear become threatening.
I've heard that the 4" .44 mag is popular with those who travel in Kodiak country but it think its purpose is for blowing your own brains out if the Kodiak gets you before you get to your rifle.
Kinda risky. I lived in Kodiak back in the early sixties. The big game guides carried double barreled 375 H&H Magnum "kill guns" with the barrels cut short for speed in the brush. Real shoulder whackers, but necessary to take down bears who got upset over being shot with some stateside hunter's favorite "06. An enraged Kodiak comes through an alder stand like it was just tall grass.