On a cruise last summer, we sat with a couple who lived one street away from the Towers. They told us they had been to vote in the local election in the school across the road, and the lady had returned home, but the man was in the street when the plane hit and the bodies started to fall.
As he told us, he dabbed his eyes with his napkin as though the sun was hurting him, but he was weeping, very quietly and with dignity, but he was weeping as he remembered what he had seen. We had eaten with this couple for a few evenings, and noticed that he walked with a stick.
When he went to the toilet to compose himself, his wife told us that he had been unable to walk properly without a stick since 9/11. His doctors said there was nothing physically wrong with him, his limp was psychosematic - the direct result of the trauma he had suffered.
Another evening, talking about careers, he told us that he had been a Navy Seal, and had a career training Navy Seals, so this man was no-one's soft touch.
His conversation talking about 9/11 and his tears, told more than I ever needed to know about how bad that day was - I will never forget him.