I have relayed this before, so apologies if you have read it previously -
On one of our cruise holidays, we dined with an art dealer and his wife - the gentleman walked with a cane. He was a Navy Seal trainer in his younger days, so no-one's idea of a soft centre.
Our conversation turned to 911, and it turns out that they live in an apartment literally round the corner from the twin towers, and on the day in question, they had gone to vote in a building very nearby.
The gentleman advised that he was walking back when the planes hit, and he saw the bodies hitting the sidewalks in front of him. As he spoke, his voice faltered a little, and tears appeared in his eyes, and he excused himself from the table.
His wife told us that since that day, he had used a cane to walk with - the doctors told him that the psychosomatic shock of what he had witnessed had affected his ability to walk, although there was absolutely nothing physically wrong with him.
I will never forget meeting this man, and his recounting of what he saw on that awful day.