Is this Death/Starvation thing common?

I left my villager's this morning with 1 Master Scientist, 4 other adults who were Adept at at least 1 skill, solved 4 puzzles, had 650 food stores and 800 crop stores, 7 shells, 5 butterflies and and found the first and second pieces of the gong.

I come back now and everyone is DEAD. I don't even recognize anyone in my village accept the slowest and least Adept i.e. the children and the slowest women who does nothing but shake her head and has zero skills.

What in the world did I do wrong?