The Great Fire of 1916
On July 29, 1916, fires which had been burning for some weeks around settlers' clearings along the Timiskaming & Northern Ontario Railway were united by strong winds into one huge conflagration. Burning easterly along a 64 km front, it largely or completely destroyed the settlements of Porquis Junction, Iroquois Falls, Kelso, Nushka, Matheson, and Ramore. It also partially razed the hamlets of Homer and Monteith, while a smaller fire caused widespread damage in and around Cochrane. The 200,000 ha holocaust took an estimated 223 lives, more than any other forest fire in Canadian history, and led to the development of improved techniques and legislation for the prevention and control of forest fires.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.