It is a common belief that, during the 17th and 18th century, insurance companies had their own fire brigades and, on attending a fire, if they found that the building was not insured by their company, they would stand by and watch it burn down.
I recently stumbled across this video from Tom Scott in which he claims that this is a myth.
https://www.youtube.com/watch?v=Wif1EAgEQKI Furthermore he paid a researcher to look into it and the researcher has produced quite an interesting report about the history of fire fighting in London.
https://www.tomscott.com/corrections/firemarks/I found it quite an interesting read.