Remembering 9/11: survivors share their stories of hope in a new docuseries

At times she can still feel the ground buckle and roll beneath her feet.

The only way she can describe it, she says, is if you closed your eyes and imagined you were standing on the biggest roller-coaster you’ve ever been on – a terrifying one where death and destruction awaits at every twist and turn.

Kathy Comerford is a survivor of the 9/11 attacks on the World Trade Center in New York, and one of the people featured in a new six-part National Geographic documentary to mark the 20^th anniversary of America’s darkest day.