I glanced out my window last night and noticed a Thai Air 747 doing a missed approach from 200ish ft. By the time I got the radio onto 27L they were telling the next plane (a Shamrock) to go round. Then "Tower is being evacuated. Aerodrome Service Ends." (I think). Then silence. However 40 secs later the Thai made two forlorn calls to Heathrow Tower -guess he hadn't heard hadn't heard there was nobody home! Last saw him at 2000ft heading off towards Terminal 5....