Answer:
Only two families survived the Donner Party without losing a single member: the Breens, who refused to share their supplies with others, and the Reeds.
Step-by-step explanation:
The party was trapped by exceptionally heavy snow in the Sierra Nevada, and, when food ran out, some members of the group reportedly resorted to cannibalism of those already dead. It was the worst disaster of the overland migration to California. Donner Lake and Donner Pass, California, are named for the party.