The "Great Meireki Fire" (Meireki no Taika) of 1657 was one of the worst disasters in Japanese History, destroying about 75 percent of the Japanese capital at Edo, and killing between 100,000 and 200,000 people.
The fire began on the 18th day of the third year of the Meireki Era (hence the fire's name), in the Edo ward of Hongô. Powerful winds from the northwest swept the fire across most of the city within a few short hours, and thousands of people were trapped and incinerated in their homes and shops before any warning could reach them. The effects of the fire and the speed with which it spread were worsened by the fact that in 1657, Edo was a city almost entirely built of wood and paper, and full of narrow, winding streets which did not serve as an obstacle to fire.
While the fire at first burned mostly across working class districts in the southeastern portion of the city, on the evening of the second day the winds reversed, and the fire began to move toward the center of the city where the aristocrats lived. Firefighters were able to save most of Edo Castle, but the main keep was damaged beyond repair and most of the homes of the retainers of the shogun were destroyed.
At last, on the third day the winds calmed and the fire began to die, but the city continued to smolder for several days thereafter, and thick, hazy smoke prevented removal of bodies or reconstruction. Finally on the 24th day of the year, six days after the fire began, work crews were able to reenter the city to collect all the bodies, which were removed to the nearby town of Honjô and buried in large pits, after which a memorial hall - the Ekôin ("Hall of Prayer for the Dead") - was built on the site, and can still be visited today.
The city took two full years to rebuild, during which time the shogunate took the opportunity to introduce numerous safegards against future fires. Major avenues were widened and new canals were dug to serve as firebreaks, retainers residences were moved farther away from Edo Castle, and a law was passed forcing all lumber yards to be relocated to the Kiba district. Not surprisingly, the unlucky reign name of "Meireki" was changed by the Emperor to "Manji" (万治) at the earliest opportunity.
Ironically, despite all the destruction it wrought, the Meireki Fire actually had a net positive impact on the Edo economy, as the shogunate distributed large amounts of money to citizens to rebuild their homes, the massive amount of new construction created new jobs and drew thousands of migrants to the city, and Edo's central mercantile district was reorganized to more efficiently encourage trade and commerce.