It's funny how many people don't seem to understand that coyotes, owls, hawks, and other predators live in cities. I had a cat taken by a coyote last year, and I live in the middle of Houston. I've had multiple cats taken by owls over the years, as well.
My college buddy had kittens taken by racoons in a partially built out suburban subdivision yet persisted in letting his cats out. I'm sorry for your losses.