[brute]

The major factor here is Berlin's street width, which was chosen to be 22m by law in 1862 for fire safety reasons, much wider than other german cities. Consequently during WW2, Berlin proved to be a problem for allied incendiary bombs. At some point they were even building a to scale model city in the desert (Dugway Proving Ground) for testing various methods of igniting fire storms.

> Berlin, however, would “prove more difficult than most other German cities”, the leading incendiary expert Horatio Bond avowed before the national commission for armament research of the USA. “The building quality is higher, and the single blocks are better separated from each other.” As the tests at the Dugway Proving Ground showed, is “was hardly to be expected that the flames would jump unhindered from one building to the next”.[1]

[1] http://www.principality-of-sealand.ch/pdf/sealandbrief0503e....

[CurtMonash]

I never knew this.

And I heard plenty of stories about the Berlin air raids from my father.