SALEM — An argument could be made that this city is defined by a fire. There is the Salem that existed before 1914 and the Salem that came afterward.
But there is no argument that on one day — June 25, 1914 — the city changed forever.
A fire that started in a leather factory on Boston Street swept across the city and down to the water, leveling hundreds of buildings and leaving thousands homeless.
"The devastation is mind-boggling," historian Margherita Desy said. After the blaze, Salem looked "the way some cities did in Europe after World War II. The only things that were upright were charred trees and chimney stacks."
In one of its most ambitious programs, Historic Salem Inc., a local preservation organization, is offering a walking tour this month that will trace the path of the 1914 Salem fire. On three successive Sundays, historians Donald Friary and Desy will lead walks following the fire route and will examine how the conflagration altered the city's architecture, economy and everyday life.
The first walk on Sept. 14 will start in the Walgreens parking lot on the corner of Boston and Proctor streets, which is where the fire began. The 90-minute tour will visit the first streets engulfed by the flames.
On the next two Sundays, walkers will go through the downtown and up Lafayette Street and end at Salem Common, which was turned into a tent city.
Organizers hope the event will draw walkers with stories to share.
"Maybe their parents lived through the fire or their grandparents," said Desy, a Salem resident and historian for the Naval Historical Center Detachment Boston, which works with the USS Constitution.
The fire is important, the historians say, for what was destroyed, what was saved and what was rebuilt.