Do you know?: - Titanic's unfavourable chain of events

 David Blair was the second officer of the RMS (Royal Mail Steamer) Titanic back in 1912. He had been the second officer of the RMS Titanic for all its test runs. But just before the Titanic could start her maiden voyage, there was a last-minute change in the plan. David Blair was replaced by Henry Wilde as the ship's second officer by the ship's owner White Star Line. Henry Wilde had been the chief officer of Titanic's sister ship, RMS Olympic. The company took this last-minute decision as they saw Wilde as a more experienced mariner with better skills of running such large ships. But David Blair became upset and wrote to some of his relatives that he was upset about being replaced. As he was upset, Blair forgot to hand over the keys of the binocular cabin on Titanic to Wilde, which changed the fate of the Titanic. As Sonar (Radar) Technology was not in use back then, the binoculars were of crucial importance, as they were the only means of safe navigation through the oceans and seas. As Wilde did not have the keys, the crew did not have access to the binocular cabin. All the crew, thinking that the ship is unsinkable, thought that there is no need for the binoculars and that their eyesight is enough to navigate the ship through the oceans. No one tried to break open the cabin door. This mistake proved fatal for the rest of the journey.
If the crew members had access to the binoculars, the iceberg could be noticed much earlier, and the collision would have been avoided.
One more fatal mistake was done by First Officer William Murdock. His decision of moving the ship away from the iceberg proved dangerous. Practically, if the ship's bow would have hit the iceberg straight, then the ship would have been survived, as only two watertight compartments would have been flooded.  Because of Murdocks' error, the iceberg hit the ship at the side which gave water space to enter more watertight compartments, increasing the ship's weight. The lack of lifeboats on the ship also added to the dangers.
By this, we conclude that the sinking of the Titanic was not accidental, but that it sank because of a chain of unwanted happenings.
The key, which would have saved the Titanic, is no doubt the 7th most valuable artifact from the Titanic, sold on 22nd September 2007 with a price tag of $135,000 (₹1,00,23,000 approx in today's rate and ₹55,82,000 in 2007).