How to revive a dead sims after not knowin they died!?

ok so last night i feel asleep without pausing my sims game n wen i woke up this mornin i had only one man left n his brothers pic wasnt there but when i came back to his gf's house it said she wanted to revive him n when i clicked on it in the wanted box it told me how but idk where to call the grim wheaper or who ever he is. i really wanna revive him cause his girlfriend jus adpoted a son and i wanted him to have a father figure in his life! but idk how he died or when any help is worth wild!