At Ground Zero, two ex-marines and an ex-paramedic join forces to search for survivors and pull off one of the most miraculous rescues of the day.
A group of firefighters were inside the North Tower when it collapsed, but miraculously survived. It's a race against time to find and rescue them.
Survivors become separated when they are enveloped by a toxic dust cloud. We follow their quest to be reunited with their loved ones.
A day of terror and the struggle to survive continues as the Pentagon is hit, Flight 93 is hijacked and the South Tower collapses.