The sinking of the Titanic is one of the most well-known nautical tragedies of all time, but some believe that a key element could have prevented it. David Blair was Second Officer on the crew before being removed at the last minute. His superiors had opted to move him off and bring in Henry Wilde, an officer with more experience with large ocean liners. Blair, in the midst of the chaos, forgot to give his replacement a crucial item: a key. Found years later, the key is thought to have been for the locker that contained binoculars for the crew. As the Titanic sailed in the days before sonar technology, the officers on ships like the Titanic had to rely on crow’s nest binoculars to detect anything out of the ordinary.

Without the binoculars, members of the ship’s crew were unable to see the iceberg until it was too late. One of the lookouts who survived the sinking of the Titanic later said that binoculars would have possibly prevented the tragedy, or at least allowed the lookouts more time to take action. No one knew about the missing key until it was auctioned off 95 years after the ship’s sinking. Blair had kept it as a memento and later passed it on to his daughter, who gave it to the British and International Seaman’s Society. Some believe that the key was not, in fact, for the binocular locker, but rather for a telephone. As David Blair died in 1955, it is likely that no one will ever know the truth behind the key and what it could have—or could have not— prevented.