The Titanic sank because it collided with an iceberg that caused damage to its hull, flooding at least five of its sixteen watertight compartments, which exceeded the ship's ability to stay afloat. The collision produced a series of thin gashes and brittle fractures in the hull plates, allowing water to flood in rapidly. Additionally, the steel used in the hull was brittle due to low temperatures, high sulfur content, and the force of impact, which contributed to catastrophic failure. The flooding caused the ship to tilt forward and the stern to rise, eventually leading to the structural failure of the midsection and the ship breaking apart and sinking. Despite claims that the Titanic was unsinkable and could stay afloat for days with up to four compartments breached, the damage to five compartments proved fatal.