The Western Battery and The Battle of York
Roughly 200 metres southwest of here (near today's Princes' Gates) was the location of the Western Battery - an outer earthwork fortification and artillery emplacement positioned to protect Fort York from a western assault. At the height of the Battle of York on April 27, 1813, an accidental explosion occurred there when a portable magazine containing artillery ammunition was detonated. The explosion killed 10 men and wounded many others. York's defending troops had fallen back to the Western Battery as the American forces pressed home their attack on the fort and Town of York. Shortly after the accident, the battery was abandoned. Regular army defenders pulled back to the garrison and prepared for withdrawal from the town. Local militia remained with civic leaders to negotiate the terms of surrender.
Plaque via Alan L. Brown's site Toronto Plaques. Full page here.