84 hours underwater, 12 minutes of oxygen left- Deepest sub rescue survivor reflects on nightmare

Roger Mallinson was one of two men rescued from a Canadian-made submersible stuck at the bottom of the Atlantic Ocean in 1973.

At 1,575 feet, it remains the deepest successful sub rescue in history.

Redmond Shannon speaks with Mallinson about how he and his colleague Roger Chapman became trapped, how the pair survived, and his empathy for the five people on board the missing "Titan" tourist vessel.