Amarillo, Texas - This may have been an American tragedy, but the sadness of 9-11 was felt around the world.
Memorial events were held in several foreign countries. In Paris, 10-story Twin Tower replicas stood tall in front of the Eiffel Tower, with a sign saying "The French will never forget". One tower had the names of the thousands who died. The other messages of support.
In Beijing, people joined hands and floated lanterns in the American Embassy pool, following a traditional Chinese custom to remember those who've died.
In Germany, they held a ceremony around a steel beam from one of the towers. They will use the beam to build a 9-11 memorial.
When it's done, it will be mounted on a block of granite, flanked by two glass towers, lit up at night in red, white and blue.