The phrase "when the world fell silent" is notably associated with the historical event of the Halifax Explosion, which occurred on December 6, 1917, in Halifax, Nova Scotia. This was a catastrophic explosion caused by the collision of two ships in the harbor—one of which was carrying munitions. The blast was so massive that it became one of the largest man-made explosions before the atomic bomb, causing widespread devastation, killing nearly 2,000 people, and injuring around 9,000. The event left much of Halifax in ruins and had a profound impact on the city and its residents. This phrase has also been used as the title of a historical fiction novel by Donna Jones Alward, which tells the story of two women affected by the explosion and the aftermath of loss, hope, and redemption in a city shattered by tragedy. So, "when the world fell silent" metaphorically refers to this moment of sudden, overwhelming disaster and stillness following the explosion in 1917 Halifax.