DSDN 104: Model broken

My 3D model that got printed out broke on me as soon as I got all the material around it off. It broke on the middle part of the model, I can understand why, because as you can see in the image below the body is so narrow and it has holes on the middle part of  model as well so that makes the model very fragile. Even though I made two models for my STL file, when I got all the material off, it looked like there was only one model that has been printed.

This is the model that I choose to get printed. The middle part of this model is really narrowed from being stretched, so it makes the model more fragile. 

Side view of the model, you can see how narrow the middle part of this model's side as well.

This is how I set up my STL file to get two models printed and I didn't even see the second model when I got all the material off, unless I've already broke the second model while I was getting the material off.

I'm not going to reprint the same model because I know it will break again because of that narrow body, I'm going to pick a model out of my iterations again then develop it and, I'm going to make sure this time the body is really thick and not real narrow.