their firsthand accounts in this documentary show that the passengers sometimes were ahead of the game. they said we're very close to land, something is wrong here. in the national geographic account of this, you get a complete picture of what happened. from the beginning to the end. >> heather: i think we have 30 seconds left. any true stories of heroism, as well? >> there were people that managed to get to the lifeboats which was amazing. the people had to swim, you forget how difficult that can be. the water was freezing cold. they had to jump from a certain level into the water and swim in. i think individual heroism, there are are a lot of couples that were going on anniversaries. it certainly is an occasion they'll never forget. >> heather: we'll definitely tune in. look forward to seeing this. make sure to tune in for italian cruise ship disaster the untold