Worst accidental explosion on board a ship

Worst accidental explosion on board a ship
Who
Mont Blanc freighter
What
1635 people
Where
Canada (Halifax,)
When
06 December 1917
On December 6, 1917, the French freighter Mont Blanc, packed with 5,000 tons of explosives and combustibles, collided with another ship in Halifax Harbour, Nova Scotia, Canada, killing 1,635 people and creating a blast that was felt more than 95 km 60 miles away.   Some sources maintain that the final death toll was over 3,000.

Published estimates of the 11,000 killed at the BASF chemical-plant explosion at Oppau, Germany on September 21, 1921 were exaggerated. The most reliable estimate is 561 killed.
This explosion is considered to be the largest man-made explosion prior to the nuclear era. 9,000 people were injured, 200 blinded by flying glass, 16,000 buildings were destroyed, 12,000 buildings were damaged and 6,000 people were made homeless.