Charles Wolf - whose wife Katherine died during the September 11 attacks - said it was "a great honour" to meet David and Samantha Cameron when the couple visited Ground Zero.
It's a great honour. It was very, very nice for both he and his wife to come. It was very personal as well as being official.
Of course they have had their own loss of their child, and when you are with someone who's had a recent loss like that, you know you are with people who get it, who care."
The Prime Minister has said he had been "bowled over" by the warmth and reception he received from US President Barack Obama.
Our Political Editor looks at the significance behind David Cameron finishing his US tour with a visit to Ground Zero.