Were all of your cats that died outdoor?
My friends outside cats kept dropping dead. They were eating/hunting poisoned rats.
Perhaps if this is the case with your kitties, you should consider asking people not to put out rat poison, or keep them inside.
Sorry for your losses.

She was the only one to actually eat anything. The first was attacked by some animal abusers down the street, and the second due to a ruptured catarac but he generally stayed next to the door(he pretty much just liked to look). But the most recent was 100% outside. She only came in when she couldnt find anything to eat. I managed to get a look at her this morning and she seemed to have just dropped dead. We suspect poisoning or some wild animal bite, but haven't thoroughly checked her yet(I kind of broke down when I looked at her after a while). But we will be looking into it. She was only around 5-6 years old and quite active her entire life, so it's very odd for her to have died with her eyes open like that. But thank you for your words.

Its always really painful to lose a pet, I'm so sorry for your loss.