The problem was heating. I don't remember the specifics but it was either a lack of coal, a lack of workers, or both. Basically everyone froze to death.
There are some YouTube channels linked form the main site at least:
In my most recent game I went immediately for setting up a petroleum industry. Exporting fuel and bitumen by train is very profitable, at least in the 60's. I invested all of the initial 1M₽ and $1M in setting it up, had 1.5M₽ in profit one year later. Set up a chemical and a plastic plant, then electronic components. I think I'll build an electronics assembly factory next, and start exporting electronics. I just need to figure out how to load a train car with the things. Rail warehouse doesn't seem to work for electronic components at least.