Total disregard of the natural circadian rhythms of employees, leads to impaired attention. Then, when an unusual or odd circumstance occurs, it often gets missed. Sooner or later the resulting chain of events concludes in an accident. Those strained employees, even if they do not fall asleep, could not possibly be on their top game under those conditions.

So what is the most common AND AVOIDABLE cause of accidents? Haavaaad MBA management types that still aren't honest enough to face reality.

Safety does cost money! Lots of it! And since no one could possibly stay in business paying costs their competitors do not have to pay; -- Add to that the myopic (or corrupt) federal regulators and politicians, that even after hundreds of sleep-deprivation train wrecks, still refuse to level the competitive playing field, by appropriate regulations; so that those who would if they could, actually would not go bust doing so.