When the news first broke of the mass shooting on a crowded street in front of the Empire State Building last month, the first thought that went through most people's heads was that another act of terror had occurred in Manhattan. Turns out though, it was an incident of workplace violence: Jeffrey Johnson, 58, who had been laid off by Hazan Imports, fatally shot an executive at Hazan, Steve Ercolino, against whom Johnson had earlier filed a harassment complaint. (Eleven bystanders were wounded by police gunfire when two officers shot Johnson, who reportedly turned and pointed his gun at them.)

It was the latest spasm of work-related violence in a country that all too often sees workplace disputes end in gunfire.

Actually, according to Bureau of Labor Statistics, overall work-related homicides declined 50% between 1994 and 2010. But workplace violence nonetheless remains among the top four causes of on-the-job fatalities when suicide is included. (At the same time, robberies are the No. 1 cause of homicides in the workplace by an overwhelming margin.)