Great Fire of Copenhagen

The Copenhagen Fire of 1728 was the largest fire in the history of Copenhagen, Denmark. It began on the evening of 20 October 1728 and continued to burn until the morning of 23 October. It destroyed approximately 28% of the city (measured by counting the number of destroyed lots from the cadastre), left 20% of the population homeless, and the reconstruction lasted until 1737. No less than 47% of the section of the city, which dates back to the Middle Ages, was completely lost, and along with the Copenhagen Fire of 1795, it is the main reason that few traces of medieval Copenhagen can be found in the modern city.

Although the number of dead and wounded was relatively low compared to the extent of the fire, the cultural losses were huge. In addition to several private book collections, 35,000 texts including a large number of unique works were lost with the University of Copenhagen library, and at the observatory on top of Rundetårn, instruments and records made by Tycho Brahe and Ole Rømer were destroyed.

The exact time that the fire started is unknown. Various sources mention times between 6:00 and 8:00 p.m., and 7:30 p.m. is the best estimate. However, the exact location of the origin of the fire is known. Almost directly across the street from Vesterport (the West Gate) was Lille Sankt Clemens Stræde. On the corner facing Vestervold, there was a small house on lot "Vester Kvarter 146" (according to the cadastre of 1699) owned by Signe, widow of Boye Hansen. The lot is almost identical to the one on the corner of present-day Frederiksberggade (the western end of Strøget) and The City Hall Square. Among the widow's tenants were restaurant manager Peder Rasmussen and his wife, Anne Iversdatter. It was on the second floor of the restaurateur's apartment that the fire started. At the inquiries held after the fire was over, both he and his wife stated that their seven-year-old son had started the fire by accidentally upsetting a candle, but it is more likely that it was the result of carelessness on behalf of the parents while casting candles and that they blamed the child to avoid punishment.

...
Wikipedia