A death on the job would fall under Worker's Compensation laws. Most, if not all states are exclusive remedy states. That means worker's compensation is the sole remedy for injuries sustained on the job, no matter what. You cannot sue your employer because you were hurt, and your estate cannot sue because you were killed. It must go through worker's compensation insurance, whether that is self-insured, corporate insured, or state agency insurance. Those benefits are set by law, and vary from state to state, but generally mean no punitive damages for an injury sustained on the job, and there is a cap on indemnity payments, although not usually on medical, at least in my state.
If an employee shoots a bad guy on the job, that bad guy can sue the employer and recover tons of cash as a result. I heard of one from an attorney where a guy stole a car, crashed, then sued the business for failing to provide proper security in the parking lot.... and won.
You do the math... slightly higher premiums for insurance when a death or injury is spread over tons of other claims, or a big payout to some guy if he survives a self-defense shooting by an employee...
Furthermore, in most states, for a single man killed on the job, there is the hospital bill and the burial costs. For a married man, there may be death benefits for the spouse, but how many delivery drivers are married? And those only last until the widow remarries.
happybrew