> When a US factory burns down and kills all the employees inside because they'd been locked in during their 15 hour shift.

I give you the Triangle Shirtwaist Factory fire in New York City, killing 146 garment workers. Same general gist, even: doors were locked by management from the outside "to prevent pilferage and unauthorized breaks".

https://en.wikipedia.org/wiki/Triangle_Shirtwaist_Factory_fi...