Mafia can only die if:
a) they are voted to be lynched
b) there is a townie who is a vigilante power role, a role that allows him to kill someone at night (kinda common kinda rare)
c) a townie is a bomb (the mafia try to kill him and the killer blows up)
Townies can die in every imaginable way:
a) lynch
b) night kill
c) vigilante
d) crazy doctor
e) bomb