Can your sims die in the game?

Yes

Yes,They Can My Sim's Died In A Fire They Can Die From A Fire thats All I know !

Yes your sim can die in a fire but don't kill all the sims in your household as it makes you restart the game from where you last saved or you have to competely restart, whoops I AM SILLY-I wanted to see what happens when you create fire and then stand next to it, I DIED

Well I know your pet can die so your Sim definently can

You can die by let your dog or cat pee next to the tv. But first you tv needs to be broken. After that repair your sim will be shocked. Second time repair it then sim dies.

Yes you can my SIMS died by a fire becaues my Sim DID NOT NO HOW TO COOK

Yes you can die you can starve them set them on fire and electrocute them thtas all I know!

Yes you can catch yourself on fire, get shocked, starve, or die of old age.
(If pets die of old age so do you)

Sims can die from fires and also starvation, but with starvation you have to stop them from going to work and you have to wait a really long time. I've done it before, though you do have to put up with their moaning. You have to send them to their home, that's the only place they can die.

I know that sims can die in this version from starvation, electrocution, a house fire, and I think that they can maybe die from sleep deprivation?
If you want to kill your sim, you need to have a plan. First things first, you need to choose how you want your sim to die, and that you're really actually sure that you want to kill them. If you don't want your other sims to cry over it and be upset, then have them avoid romantic and friendly relationships at all costs. You also need to figure out how exactly you want to kill them. By this, I mean that, for example, let's say you want to burn your sim to death.
Of course, you'd actually have quite a few options for burning them to death. First of all, if you want them to create a house fire, then you'll need to create / use a sim that is a horrible cook, and does not have the cooking trait.
The first thing you'll need to do for killing your sim in a house fire is to make sure that you've either sold or put away all of your fire alarms. If you have fire alarms, then the fire department will come and rescue your sim from the house fire.
If there's certain items that you don't want to get damaged, destroyed, or completely burned, then put those into your inventory. I would highly suggest that if you have other members of the household, to obviously do this while they're at work so that they don't try and extinguish the fire.
Now, if you want to kill your sim by electrocuting it, you'll need a few or so play coins in order to buy the "shock" power-up. Once you've bought the power-up, select the sim you want to murder. Use the power on them, and once you have, the game will warn you to keep them away from electric appliances for the next few days, or they could possibly get electrocuted and die.
Now, if there's a broken appliance in the house at all during the next few days after their shock experience, then you're in luck! Get the sim you electrocuted to try and fix the electric appliance. If you do, then they're dead. :-)

And finally, sleep deprivation. I mean, at least, after all... I kinda think there's death by sleep deprivation, right? Okay, so basically, to kill a sim via sleep deprivation, you need to do one simple thing:
Lock the sim in a room by removing all doors, and after you've moved that certain "lucky" sim into the room, make sure that there are absolutely NO other sims in the room, or they could possibly die from sleep deprivation as well. The next thing you need to do is remove all chairs, couches, and beds from the room. Within a few days, the sim will either die of exhaustion (sleep deprivation) or die of starvation (lack of food).

Now, to kill a sim by starvation, all you have to do is either lock them in a house or room of a house, then remove all sources of food (stove, fridge, toaster, old plate of food) from the room, and then wait a couple of days. If you don't want them to die of sleep deprivation, then you can always add a bed and perhaps a bookshelf into the room for them, since it won't affect their hunger. They should be dead within a couple of days or so, due to lack of food.
Thank you for your time, and your wonderful question(s). I will be seeing you next time, with my very informational responses to your Sims 3 Pets - 3DS Edition questions. This has been Kelsey, the answer to your questions. Or should I say answer-er? Ahaha! Have a nice day!
- Kelsey Simmer