The tragedy of the ill-fated Germanwings flight in March, and speculation about the reasons why the co-pilot may have intentionally crashed the airplane, has raised troubling issues for employers. Amid speculation that the co-pilot may have been depressed and suicidal, and may even have obtained a doctor’s note to not report for work on the fated day, many in the media and around the water cooler have wondered, “How did the employer not know?”