the question is for my business law 140-505 class

Koby, age 18, works after school at FastFood from 4 p.m. until 11 p.m. On Friday night, the restaurant manager sees that Koby is exhausted, but insists that he remain until 4:30 a.m., cleaning up, then demands that he work Saturday morning from 8 a.m. until 4 p.m. On Saturday afternoon, as Koby drives home, he falls asleep at the wheel and causes a fatal car accident.

Should FastFood be liable?

What important values are involved in this issue?