[2020] my game crashes my whole pc

Firstly make sure you define a pagefile size, so the game has all the memory it needs. Most crashes are from running out of memory or from Windows expanding the pagefile a tiny bit a ton of times. This guide explains how to set a pagefile size. I recommend setting it to 32 GB.

https://steamcommunity.com/sharedfiles/filedetails/?id=2114415052&searchtext=pagefile

That might do the trick, but you might also still have problems. If you're using workshop content, try adding the launch option -noWorkshop and start a new city. Does it happen then as well? Or does it run fine with that launch option in place?

Here's how to set launch options in Steam: https://support.steampowered.com/kb_article.php?ref=1040-JWMT-2947