Souraya, I really don't know how the door got opened.... It is an old house and this winter we did have some trouble with it. It would expand or shrink with the temperature changes and I have seen it pop open before. It hasn't done it in a really long time and I honestly didn't think about it.... It is locked and chained today!
There is another strange thing that happened the other day that is making me suspicious....a few weeks ago Duncan bit the neighbor, the college kid that lives on one side of me. He was on a leash but I had forgotten his collar so I had 2 leashes hooked together and looped around his neck. So I underestimated how far he could reach. The silly neighbor reached down to pet him and before I could tell him not to touch him, Duncan bit him in the arm. The bite didn't break the skin but it did rip his winter jacket. I told him I would buy him a new winter jacket for $200 IF he didn't turn Duncan in to the health department. I didn't want Duncan to get in trouble and since the bite didn't break the skin, I saw no reason to report it. I gave the neighbor a copy of Duncan's rabies certificate for his records and peace of mind. Well, a few days later, I received a letter from the health department telling me that they had received notice of a bite and that Duncan had to be quarantined for 10 days. I called a friend of mine at the health department and he didn't have to go away for 10 days after all. But I was so angry at him. So I didn't give him the $200. Perhaps I'm wrong but I refuse to give him any money....he will have to sue me now and I don't think he will. So anyway, he and I had a "discussion" about this the same day that Duncan got out. So I am a bit concerned that he did something to Duncan. Our front door window has a crack in the plexiglass that is large enough to stick a hand through.... I don't think he would do anything but it is a coincidence.
I am moving on May 3rd however to an apartment by myself with Duncan. I can't wait! I can't have all these unknown variables in Duncan's life. It's not safe for him and I need a place for him where I don't have to worry about others.

Anyway, he is feeling fine now and if I can just get through the nest week and a half, he will be safe!!