Since around 2 o'clock UTC time, I notice that all (or almost all? point me out if I'm wrong) submissions are "In queue".

At first, I thought this was just a temporary server error. However, codeforces has been down for 9 hours already as for now, and it still shows no sign of recovering, and nor did I find any annoucement about this.

Can anybody tell me what has happened? And perhaps predict when codeforces will come back to life?