Because Murdock was a idiot and tried to swerve a ship 883 ft long he sideswiped a Iceberg over 100 ft. tall breaching more compartments than the ship could survive. Titanic had 15 water tight compartments, which was great except they only go up to E-deck. Now if you close the watertight doors, once the bow sinks down to E-deck the ship is going to sink way faster because now the water is not only coming through the holes the iceberg made, it's also pouring over the tops of the watertight bulkheads, but because it's just in the bow the lights are going to stay on longer. Ok if you leave the doors open the water fills the whole ship up and it's only coming in through the holes that the iceberg made, but you are going to lose all the power fast because the boilers are in the bottom of the ship, but you will stay afloat at lot longer this way because the water is only coming in through the holes and not pouring in over the top of the bulkheads on E-deck. Titanic sank at 2:20am and the Carpathia started picking up survivors at 4:30am. In Murdock's defense the doors close automatically when water is detected, but he could have manually opened the doors. I am not saying the ship could have stayed afloat for another 2 hours, because eventually the bow would sink down past E-deck and once that happened the water would have been coming over the top of the bulkheads in addition to coming through the holes the iceberg made. What I have always wondered is why nobody tried blocking the holes enough so the bulge pump could keep up. Doing that, the Titanic could have stayed afloat and not needed to be rescued at all. The air temperature was 28*f there was no moon, I don't want to get anywhere the water that cold. I would have grabbed some mattresses and dropped down in a life boat and used an oar to try to stick a mattress in one of the holes.