Aw Sketch sounded like such a great cat. I'm so sorry he passed away, Its too bad you couldn't find out what happened to him. I can understand why you don't want another cat right now, but sometimes the best way to help get over a loved one is by occupying your time and love with another.

But in your case it may not be, who knows.

One again, I'm very sorry about your kitty

Rest in Peace Sketch.