According to the article, "Most people make between $16.50 and $20 an hour".

So, at 84 hours a week (46 normal pay, 38 overtime at 1.5x), thats $1700/week on the low end, or $88k/year.

I dont think that excuses the forced overtime and I would absolutely expect severe health and/or mental health issues to result from the overwork. But, these people can quit (and according to the article many do) - I expect the only reason folks do stay is because they cant make the same money anywhere else.