Roselle the 9/11 guide dog

After the 9/11 terror attacks in 2001, a New York guide dog called Roselle was hailed as a hero for helping her owner safely down 78 flights of stairs and away from the Twin Towers before they collapsed.

In this programme, first broadcast in 2017, Simon Watts speaks to Roselle's owner, Michael Hingson.

(Photo: Roselle and Michael Hingson, right, meeting a 9/11 rescue team. Credit: Getty Images)