Death
Death is a state in which a sims dies. The wats they can be killed by are fire, shock, starvation, flies, being eaten by the cowplant and being scared to death. If there is a living sim around they can plead for their loved one with the Grim Reaper but it doesn't always work. The dying sim and the Sim pleading for his life must have a very good relationship.
In Sims University there is a special item, the Resurrect-O-Nomitron (?) which can restore Sims but for a hefty fee of up to 10.000 simoleons. If the Sim who wants to bring another Sim back, pays only very little, the dead Sim can return as a zombie.