For example, Amazon has 950k employees in USA. Among Americans aged 45-54, 80 people per 100k die each year due to cardiac reasons. If 10% of Amazon workers are 45-54, and Amazon doesn't employ anyone over 54, at least 76 Amazon workers will die due to cardiac reasons.
1/3 of cardiac deaths occur suddenly.
If average worker spends 40 hours per week in work (23% of time), 75 * 1/3 * 23% = around 6 Amazon employees in US will die in work each year, without any wrongdoing on any side.
Moreover, poor people are at significantly increases risk of sudden cardiac arrest - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3193117/ This may or may not be related to work conditions (though, I suspect rather combination lifestyle and healthcare access).
Though, physical labor is associated with increased early mortality in men, but causes aren't clear (I suspect it's lifestyle, because women doesn't display such correlation). https://bjsm.bmj.com/content/52/20/1320