Charles Woolf recalls wife Catherine's 9/11 killing
9 September 2011 Last updated at 11:56 BST
This weekend marks 10 years since the twin towers in New York were attacked and later collapsed.
Thousands of people in the World Trade Centre, and on the planes that crashed into them, lost their lives in the 9/11 suicide attacks.
Charles Woolf lost his wife Catherine in the twin towers. She was originally from Swansea.
Radio Wales' Oliver Hides asked him to recall what he remembered of that fateful day.