It commemorates those who were killed or suffered injury, and those who lost homes and family when the munitions ship, Mont Blanc, blew up in Halifax Harbour.
It also honours the survivors, who rebuilt the cities of Halifax and Dartmouth in the years that followed.
Over 1,900 people were killed immediately. Within a year the figure had climbed well over 2,000.
Around 9,000 more were injured. Almost all of north-end Halifax and north-end Dartmouth, were destroyed.
Money poured in from as far away as China and New Zealand. The Canadian government gave $18 million, the British government almost $5 million, but most Haligonians remember the generosity of the state of Massachusetts, which donated $750,000 in money and goods and gave unstintingly in volunteer assistance through the Massachusetts-Halifax Relief Committee. To this day, Halifax sends an annual Christmas tree to the city of Boston in gratitude.