This is very sad!
Usually when conflicts between what you have in your computer (probably erased after the blue screen) and what Steam have in the cloud gets in conflict, you receive a warning asking what you want to do: upload your version or download the version from the cloud. You didnt get this warning?
You can also hope your offline version is all right and try to make it work. Now I'm just completely guessing, no knowledge about it, you can go to the maps folder of the game and rename the saved game file, if its there and reload the game. Your saved game is here: C:\Users\%USERNAME%\AppData\LocalLow\Colossal Order\Cities in Motion 2