Cause of my rats death

Question
I originally had 2 pet rats (they where sisters). The first one died around 2 months ago and the other died yesterday. I was a little confused about the reason for the death though. For the last week or so she had seemed weaker, not eating/drinking as much, so I thought maybe she was on the way out (I had no idea how old she was) but gradually she seemed to start eating/drinking again but she was always lying down, she didnt seem energetic like she used to. Anyway I got home from work yesterday and found her dead, in my cage there is a ramp, there is a small gap between the edge of the ramp and the side of the cage, the rat was wedged between this gap,  the edge of the ramp looked like it was crushing her neck. I had to pull really hard to get her unstuck, her pupils had turned white. Now this really confused me, for a start I couldnt understand how she managed to get in this position in the first place as the gap is really small, it looks to me like the ramps edge crushing her caused the death, but surely rats dont commit suicide if they are in pain? Maybe she was trying to get a piece of food and got stuck? I dont know, does the white pupils point towards a cause of death? My first rat died in the middle of the cage and did not have white pupils, im thinking maybe the second rat choked to death which could maybe have caused the white pupils? I dont know, honestly dont have a clue im just using guess work based on what I saw. If you can think of something which might have caused the death that would be great, I just need help understanding how this might have happened.

Answer

I am very sorry for your loss.  

While accidents do happen, this doesnt seem to be what happened. Usually the old saying applies to rat: What goes in must come out.  Chances are if she got wedged in between something she would get out again.  Rats can fit through very tiny spaces you would be surprised.

The white pupils are more than likely due to decreased circulation and the longer they are dead, the more changes take place to the rats body.

What caused her death is hard to say. It could have been anything from a stroke or heart related.