I was in central Moscow on 9/11 at my mother-in-law's apartment. They interrupted local programming on TV after the first plane hit and were showing a live feed of the burning building. Speculation from the announcers was that there seemed to have been an accident but they didn't know what was going on. We then watched the second plane collide and at that point it was obvious that this was a terrorist attack. We continued watching live as the buildings ended up coming down. After watching for a while, we went out for dinner and the next day I flew with my wife and daughter from Moscow to Warsaw.
I remember seeing a lot of support in Moscow at the time for the US, and at the time Russia had recently suffered a number of horrible terrorist attacks themselves. In Warsaw there was tremendous support for the US and emotional signs of unity against the insanity and suffering that had occurred. We were at the US embassy in Warsaw a few days later and there were piles and piles of flowers that locals had put out in memory of the 9/11 victims. It was very strange being out of the country during probably the most "defining" event for America since i was born (I'm 47) and just watching it from afar, even though I'd been living abroad at that point for about year. It's also strange to be able to say I flew on 9/12. I flew back to the US (Warsaw to Atlanta) on 9/21, and I remember our flights being very cheap even though we bought them with almost no advance notice.