00:00 On December 6, 1917, the Halifax explosion killed 2,000 people in the harbor of Halifax, Nova Scotia.

01:51 The city of Halifax, Nova Scotia was an important port connected to the Canadian Pacific Railway and served as a stop for ships carrying supplies to Europe during World War I.

03:15 A French freighter loaded with explosives and flammable material called the SS Mont Blanc was heading north in the harbor and blew its whistle to indicate that it had the right of way, while another ship called the SS Emo was sailing out of Bedford Basin at a high speed and on a course that would cut off the Mont Blanc.

04:42 The collision between the SS Mont Blanc and the SS Emo caused the Mont Blanc to catch fire and the captain ordered his crew to abandon ship.

06:10 The explosion of the SS Mont Blanc was the largest explosion in human history up to that point, causing widespread devastation and resulting in immediate deaths, injuries, and destruction of buildings in Halifax.

07:43 The explosion resulted in over 1,700 confirmed fatalities, with an estimated total death toll of up to 2,000, and it disrupted communication between Europe and North America; relief efforts were further hindered by heavy snowfall, but the crew of the Mont Blanc, who knew about the impending explosion, managed to escape and avoid significant casualties; the Halifax explosion was ten times greater than the 2020 explosion in Beirut, and while the community initially struggled to commemorate the event, there are now several monuments and traditions in remembrance.

09:20 The Halifax explosion is the largest accidental explosion in history and one of the largest non-nuclear explosions ever, and it is commemorated every year with the official Christmas tree of the city of Boston.