It’s hard to see this disaster as an Occupational Safety issue. That concept is based on the presumption that the owners are willing to tolerate the occasional death or maiming of a worker for the sake of lower cost of production. In this case, the owners lost their whole plant before it ever went into production.
So, why did it happen? This purging process as I’ve seen it roughly described would seem to be as obviously dangerous as it is crucially important. Just for that reason, I would think everyone at all levels would be very focused on it. Of course, by the time umpty different investigations are concluded and as many court cases fought over, it will be just a dim news memory.
Cause of the accident - Highly skilled Union Labor (who of course were on a break while unskilled apprentices were doing the wok)