Now I have a kitty problem

This time of year my indoor kittys get the urge to go outside. Especially Buzz. He has bolted once before but came back a day later to eat. This time, Saturday, he shot out the slider as I was letting the dogs back inside. I havn't seen him since. I'm worried sick about him. He has been an indoor kitty since he was 4 weeks old, his 2nd birthday is in two weeks.

Please send vibes that he is safe and that I will see him soon. I would also like to hear your stories about indoor kittys escaping.

My adults all figured out how to let themselves out the back door last year. For a while (until I figured it out) I had no idea how they'd manage to both come running up to me minutes after I went outside. Even more baffling was continually coming home to see my big grey girl casually perched on the roof, watching me. (Luckily, she never fell off, though she came very close a few times! I'd lure her down with food.) Then one day, I heard a noise and watched the door. Sure enough, they both snaked their way out and came running. This did not bother me very much, as they never went out of sight, but then they began the "mad dash for the door the second it opened" habit. From then on, I kept the back door locked when I went out, and kept them inside. In a short while, the habit was broken.(they are both strictly indoor now)

Mine our inside/outside but with restrictions. Two have collars with bells but we have 5 acres and the other two really don't go farther than a 100 feet or so from the house.
If we aren't home-they are inside!!