I am so sorry for your loss. It doe bring the point home that there are too many dangers out side. Our CREW is not allowed out, they have thier cat trees, windows, and a ton of toys. Yes they do go to the windows and doors, but most the time they do not what to go out, just look.
The average age for an out door cat is 4 years, an indoor cat is over 15 years. Think about it.