The SS Mont-Blanc was loaded with explosives and a fire started after the collision. The fire quickly spread and caused a large exploration when it made it to the cargo hold.
The explosion caused almost all structures within a half mile radius to be destroyed. Approximately 2,000 people would lose their lives as a result of the explosion. 1,600 deaths occurred at the time of the explosion, with over 300 dying afterwards. 9,000 people were injured. 25,000 people were left without proper shelter because of the explosion.
Damage to structures occurred up to 1.6 miles away.
Patrick Vince Coleman, a dispatcher with Canadian Government Railways (the former Intercolonial Railway of Canada), helped to avoid a number of deaths from occurring. When he heard from a sailor about the contents of the SS Mont-Blanc, he returned to his desk to signal an inbound passenger train in order to stop it from coming into its destination of Halifax. He would lose his life for his actions, but his warning stopped the train from making it to Halifax, and saving the lives of those aboard the train.
To this date, every Christmas the City of Halifax sends a Christmas tree to the City of Boston for their relief assistance in the aftermath of the explosion.
The explosion remains the largest non-nuclear explosions in history.