Game Not Found after few days inactivity

I have been playing a game with a couple of friends. None of us have logged in for various reasons for about 4 ot 5 days. Today I try to resume the game and it is missing. When I use the direct link to the game I get the message 'Game Not Found'. The game was a casual game for beginners called 'World War 4' created by me. Why would the game disappear like this? If there is a period of inactivity before a game gets deleted where does it say this in the documentation? Should I not have been informed that the game was about to be removed?

I've just checked my game statistics and it shows that I have 67% games abandoned. I did not abandon any game, it just simply disappeared

You timeout if you aren't active for 3 turns if I remembrer well, and if all the players timeout the game is finished.

Thanks Sator, that makes sense. Problem is though it doesn't mention that anywhere in the rules. Or at least I couldn't find any mention