Today is the 20th anniversary of the 9/11 attacks, a series of coordinated terrorist strikes in the US that killed almost 3000 people and changed the world forever.  Our guest for this single, Hans Kunnen, was one of several Australians in New York that day and has told his story many times over the last 20 years. But what struck us about his story was not how close he was to the action, or how he described the flames, the smoke, the hurtling bodies.It is how he talks about the kindness of a stranger - the hope amidst the chaos of what was the most traumatic day of his life.