There was almost certainly drugs or some sort of heart condition involved. Unfortunately, congenital defects can go unnoticed until circumstances like these.
The idea that three long days, alone, is what killed him is ridiculous. Going a few days with just a couple of hours of sleep a night is something many people do at points in their lives (e.g. working parents with small children when they get sick). And the "100 hour" weeks mentioned in the article are stressful, but again, nothing a working mom (or dad!) with a baby hasn't experienced.
people can survive a week with no sleep, while performing physical labor 24/7...all without dying
Sure, most people can survive like that. Others probably can't. I would like to think that being a banking intern is less physically taxing and dangerous than being a Navy Seal.
Amusingly enough I read something not too long about about how if someone falls asleep during a meeting or at work (in Japan) it is respected because it is assumed they fell asleep through overworking.
True. It is highly unlikely that sleep deprivation alone killed him.
However, there were a few studies performed on animals where the test subjects died after 5-20 days of (complete) sleep deprivation. There does not seem to be a study about the long term effects on humans.
So it might be possible to kill someone from sleep deprivation - it might just take a while.
The idea that three long days, alone, is what killed him is ridiculous. Going a few days with just a couple of hours of sleep a night is something many people do at points in their lives (e.g. working parents with small children when they get sick). And the "100 hour" weeks mentioned in the article are stressful, but again, nothing a working mom (or dad!) with a baby hasn't experienced.