The cargo ship SS Mount-Blanc carrying high explosives collided with the SS Imo just off of the docks at Halifax and caught fire on December 6, 1917. The Mount-Blanc caught fire and at 9:04 AM the Mount-Blanc exploded.
The explosion was measured at approximately 2.9 KT, To put that into perspective it was about 20% the size of the nuclear bomb that hit Hiroshima.
1782 people died, about 9000 injured. The blast wave devastated Halifax to the tune of a blast radius of half a mile.1600 homes were destroyed and 12,000 damaged. 6000 people were left homeless.
Just to put the sheer size of this explosion. the massive Beruit explosion was between .3 and .6 KT, or between 10% to 20% the size of the halifax explosion.
