Not everyone in Malton dies, but if you do, it's probably not your lucky day. This page tells you what happens after you die.
Death for Survivors
When survivors die, they become a zombie. From then on, they could choose to just play as a zombie until a Survivor with the proper abilities revives you. This will bring you back to life, able to stand up as a breathing human for 1-10 Action Points (AP). This means one would need the help of others to be resurrected, and it can be hard to communicate to others that one wishes to live again. One's best bet (using in-game communications) is to find someone with the Lab Experience skill, and politely "Mrh?" at them. If you know where Necrotech buildings are, standing outside one of those is a common signal that you wish to be revivified, although it is best to stand one block away from them, and not directly outside them, as you could be seen as trying to attack the building. Lastly, some zombies have been known to possess the (amazingly common) "Internet" skill, and use forums, e-mail lists or message boards to request revivification. If revivified, you will retain all XP you have earned up to revivification.
Death for Zombies
When zombies die, it's an inconvenience. Any zombie can stand up after dying for 1-15 AP, depending on whether or not they possess the Ankle Grab skill, and if they have been Headshot. They retain all skills and items they previously possessed, as well as all XP.
Is Death Permanent?
No, there is no way for any character to be permanently killed. Any transition from human to zombie or zombie to human is completely reversible. Even zombies who have chosen to buy the Brain Rot ability can be revived inside powered Necrotech buildings.