Nearly 25 years after the September 11, 2001 attacks, survivors are concerned that memories of the tragedy are fading.

Orthopaedic surgeon Gordon Huie, who helped treat victims after the twin towers collapsed and lost his sister Susan in the attacks, now speaks publicly about his experience.

Suffering from cancer linked to Ground Zero dust exposure, Huie says that younger generations often know little about 9/11.

As the US approaches the attacks' 25th anniversary, he hopes remembrance will focus on the victims and survivors rather than political divisions.