Updated

Somber ceremonies are taking place in Halifax to mark 100 years since the Canadian port city on the Atlantic coast was devastated by a wartime blast that killed approximately 2,000 people and injured an estimated 9,000 others.

The catastrophe, known as the Halifax Explosion, remains the worst human-made disaster in Canadian history and was the world's largest human-made blast until the detonation of an atomic bomb in 1945.

The explosion on Dec. 6, 1917, was ignited by a collision between the French ship SS Mont-Blanc, which was laden with explosives, and the Norwegian vessel SS Imo in the strait connecting Halifax Harbour with Bedford Basin.

A large crowd turned out Wednesday at the Fort Needham memorial site, not far from where the explosion wiped out the city's north end.