You know one of the people who died (a child) was extremely concerned about the safety of the sub, right? The CEO mislead and lied. To blame the victims here is disrespectful to say the least.
The attitude that you have no responsibility at all for confirming the safety yourself, simply because a salesman says it's safe, despite clear existing public evidence they could have easily discovered that it's not, is collaboration in evil.
It's always easy and comfortable to falsely deal in absolutes, black and white, that one guy is the bad one and the other voluntary participants were the "victims". 100% vs 0%. But doing so is what lets people get away with aiding and abetting wrongdoing.
That "child" was a 19 year old university student, which is beyond draft age. He made his choice. Not that that exculpates the role of his mother in his death.
This position is disrespectful of everyone who doesn't make such reckless, and mostly showing off driven, risks.
So simple thinking could view this as some wreckless narcissist CEO defrauding some naive customers, and hence a "tragedy".
But alternatively, since the CEO's attitude and the safety record was publicly known, you could instead interpret it as an elaborate suicide pact.