Quiz: what was the single biggest explosion in WW1?

The Halifax Explosion in 1917. It occurred as the result of a naval collision between two ships. A fire ensued and grew out of control within minutes. The resulting explosion was the largest man-made explosion until the nuclear bomb.

As far as I am aware Canada forms a large part of the American continent.

Are you still sure it only rarely appears in American history books?

Is the question "Why do the history books of the United States rarely mention the history of Canada?"

The Halifax explosion in Canada,6 December 1917.

It was the largest man-made explosion until nuclear weapons were developed.

The SS Mont-Blanc Explosion.

Hailfax explosion

Kabooom!!!

T̶h̶e̶ ̶d̶e̶t̶o̶n̶a̶t̶i̶o̶n̶ ̶o̶f̶ ̶t̶h̶e̶ ̶m̶i̶n̶e̶s̶ ̶a̶t̶ ̶L̶a̶ ̶B̶o̶i̶s̶s̶e̶l̶l̶e̶,̶ ̶S̶o̶m̶m̶e̶

[I am obviously wrong, Ammianus has given an answer which amazes me.]