By 'I'm not there' I assume you mean that the game is not running. In that case the event will appear when you next turn on the game. Note that if you don't turn on the game for several days, the events that would normally happen in that time will not appear. You will just get the one event.

If you leave the computer with the game running the situation is similar; the event will appear on the screen and stay until you return to make a choice or press OK. The game will still go on in the background, though. You'd probably see the figures update and the villagers rearrange themselves once you do press the button. The next event will be scheduled from the time you press the button.