According to the granddaughter of the second officer aboard the Titanic, Charles Lightoller, The Titanic sank from human error. A new steering system led to a mistake by the steersman, into going "hard a port" instead of "hard a starboard" and straight into the iceberg instead of away from it.
According to the second officer's ancestor, a Charles Lightoller was the most senior officer to survive. He kept the secret from two separate inquiries because, according to his granddaughter, he saw it as his duty to protect the White Star Line from bankruptcy. He only told his wife the truth. His family kept it secret after his death to protect his reputation. He was a twice decorated war hero.
To make matter's worse, the chairman of the White Star Line, owner of the Titanic, ordered the ship to keep sailing. If they had stayed still as the captain had wanted, the ship would have taken hours to sink. Long enough to rescue everyone aboard. Instead, 1500 people died.