This version of events is confirmed by General Armand de Coulaincourt. He states that they had been in Moscow for three days. That evening a small fire had broken out but was extinguished and 'attributed to the carelessness of the troops'. Later that evening (10h 30min) Coulaincourt was waken by his valet with the news that 'for three quarters of an hour the city has been in flames'. Fires continued to break out in multiple separate points. Incendiarists were arrested and interrogated and declared that their commanding officer had ordered them to burn everything. 'Houses had been designated to this end.' Later on in the same chapter he asserts 'The existence of inflammable fuses, all made in the same fashion and placed in different public and private buildings, is a fact of which I, as many others, had personal evidence. I saw the fuses on the spot and many were taken to the Emperor.' He goes on to write 'The examination of the police rank-and-file… all proved that the fire had been prepared and executed by order of Count Rostopchin'.
La Grande Armée, that set its position in a military camp manner and was carelessly looting sellable valuables, had also its share of responsibility: many buildings caught fire from bonfires they made for cooking. In any case, the catastrophe started as many small fires, which promptly grew out of control and formed a massive blaze. Napoleon's police measures and executions of "arsonists" were put into effect after much of the city was already ablaze.
Tolstoy, in War and Peace, suggests that the fire was not deliberately set, either by the Russians or the French: the natural result of placing a wooden city in the hands of strangers in wintertime is that they will make small fires to stay warm, cook their food, and other benign purposes, and that some of those fires will get out of control. Without an efficient Fire Department, these house fires will spread to become neighborhood fires and ultimately a city-wide conflagration.
Ivan Katayev (1911) summarized losses as 3/4 of all properties in the city:
An estimated 2,000 wounded Russian soldiers perished in the fire. Moscow State University, Buturlin's library, Petrovsky and Arbatsky theaters were completely destroyed; many pieces of art, notably the original of The Tale of Igor's Campaign, were lost forever. The Moscow Orphanage near Kitai-gorod, converted to a hospital, was saved by local police. The population of Moscow in 1811 is estimated at 270,000; after the war, when residents returned to the city, it decreased to 215,000; by 1840, it had increased to 349,000 (Filippov).
Maps compiled by Russian authorities after the war (notably the 1817 military map reprinted for the public in the 1831 guide book) show that the majority of Moscow territory had succumbed to the fire. Notable exceptions are Moscow Kremlin, the Orphanage, northern segment of Bely Gorod from Tverskaya Street to Pokrovka Street, Patriarshy Ponds in the west, as well as suburban settlements.
The map probably exaggerates the damage, showing some surviving blocks as if they were destroyed. For instance, Bolshaya Nikitskaya Street west from Boulevard Ring retained many of its mansions: troops defended their own lodgings and the French theatre, as well as the French colony in Kuznetsky Most. On the other hand, French patronage did not help the Batashov Palace (present-day Yauzskaya Hospital), occupied by Murat's headquarters: after two days of firefighting, it was consumed by fire that razed Taganka. Still, the remaining buildings had enough space for the French army. As General de Marbot reasoned, "It is often claimed that the fire of Moscow… was the principal cause of the failure of the 1812 campaign. This assertion seems to me to be contestable. To begin with, the destruction of Moscow was not so complete that there did not remain enough houses, palaces, churches and barracks to accommodate the entire army" (for a whole month). However, many units were stationed not in the city, but in remote suburbs like Ostankino (light cavalry) or Khimki (Italian corps); others were dispatched south to screen Russian movements.
The disaster allowed the authorities a unique opportunity to plan the city from scratch. In February, 1813, Alexander I of Russia set up the Commission of Building in Moscow, with the instruction to produce a viable master plan for the city. The 1813 plan by William Hastie was deemed inadequate for the task, thus the Commission hired numerous local architects and topographers who produced the final, 1817, master plan (incorporating Hastie's ideas of clearing the Central Squares of Moscow). In 1816–30, city planners set up the Garden Ring, a circular highway in place of an old fortification rampart, and widened many other streets.
Later in 1817, the city held groundbreaking ceremony for Alexander Witberg's Cathedral of Christ the Saviour, a monument to the 1812 War in Sparrow Hills. This project was later canceled and the actual Cathedral emerged in the center of Moscow.
Reconstruction of Red Square and Kitai-gorod was handled by Joseph Bove, who designed the neoclassical Upper Trade Rows as a mirror of Matvey Kazakov's Kremlin Senate. In February 1818, Ivan Martos completed the Monument to Minin and Pozharsky, the first public monument in Moscow, placed in the center of Red Square. Bove also designed the symmetrical Theatre Square and completed Bolshoi and Maly theaters by 1825. Moscow University and other public buildings were rebuilt by Domenico Giliardi and Afanasy Grigoriev.
Bove also handled the "façade department", authorizing façade designs for all new buildings. A severe shortage of brick, stone and cement forced many developers to build in wood; the city had to agree with the inevitable, on condition that the houses follow the neoclassical standards. Local craftsmen responded with mass-produced wooden imitations of classical ornaments. Most of these houses were eventually destroyed. Extant examples include a recently restored house on the corner of Glazovsky and Denezhny Lanes in Arbat District, and Vasily Pushkin house in Staraya Basmannaya Street.