Source (Page 90)
...when General Dearborn planned his attack on York the command of the expedition was given to Pike... . It was on the 27th of April 1813 that the tragical assault was made.
The slaughter was terrible. Yet the enemy resolutely held his ground until Pike, with the main body, had effected a landing. Quickly forming his men, Pike dashed on in pursuit.
The troops, being fatigued, the leading regiments were allowed to seat themselves on the ground; Pike himself, surrounded by his staff imitating their example. In this position they were awaiting the effect of the artillery when suddenly an explosion occurred shaking earth and sky. Instantly every man looked around in horror.
The explosion was seen to proceed from a magazine of the enemy, a huge stone building which had caught fire by some untoward accident. The Americans were all within a compass of a few hundred yards right in the track of this terrible volcano.
Over three hundred individuals by that fearful descent were hurried into eternity or else wounded or maimed for life. Pike was one of the sufferers.
Seeing the huge masses in the air and knowing that escape was impossible he did not attempt to rise but stooped his body forward instinctively. A piece of the wall struck him on the back as he bent in this position and gave him a mortal injury. Just as he was lifted from the ground he heard a shout and inquiring what it was for was told the enemy's flag was coming down.
He lived but a few hours... .