while the Titanic was sailing across the icy waters of the North Atlantic , a huge iceberg was suddenly spotted by a look - out . After the alarm had been given , the great ship turned sharply to avoid a direct collision . The Titanic turned just in time , 20 narrowly missing the immense wall of ice which rose over 100 feet out of the water beside her . Suddenly , there was a slight trembling sound from below , and the captain went down to see what had happened . The noise had been so faint that no one thought that the ship had been damaged . Below , the captain realized to his horror that the Titanic was sinking rapidly , for five of her sixteen water- 25 tight compartments had already been flooded ! The order to abandon ship was given and hundreds of people plunged into the icy water . As there were not enough life - boats for everybody , 1500 lives were lost .