(FORTUNE Magazine) – THE SHOOTINGS ON Jan. 26 at a Jeep factory in Toledo bring to mind an eerily similar episode of violence that is likely to have serious legal implications for all U.S. employers. On a scorching-hot day in July 2003, a worker named Doug Williams at a Lockheed Martin airplane-parts plant in Meridian, Miss., stood up in the middle of a mandatory ethics meeting (yes, a meeting about workplace ethics), went out to his car, and came back with several guns. Williams then shot six co-workers to death and wounded eight others before committing suicide.

If these were isolated incidents, it would be easy to dismiss them as tragic flukes, irrelevant to what's going on where you work. Not so fast. Most occurrences don't make headlines, but the Bureau of Labor Statistics reports that in 2002 (the latest year for which figures are available), U.S. employees at work were the victims of 18,104 injuries from assault and 609 homicides. No wonder the Centers for Disease Control has called workplace violence a "national epidemic."

The horror in Meridian has left Lockheed Martin shaken and grieving--and possibly open to unlimited damages from pending lawsuits. In a little-noted court decision last fall, a judge rejected the company's bid to have its liability limited by workers' compensation (which in Mississippi would put a ceiling of $148,977 on each claim). Instead the court found that being shot at was not within the scope of workers' duties and could happen anywhere in our gun-happy society, so workers' compensation law does not apply. Lockheed Martin is appealing the decision, and several lawsuits against the company are suspended in the kind of legal limbo that can drag on for years and cost millions. In the end a precedent could be set that could turn workplace-violence litigation into a costly quagmire.

Given that kind of risk, why aren't companies doing more to address the problem? A recent study by the American Society of Safety Engineers says that just 1% of U.S. employers have a formal antiviolence policy --despite the fact that OSHA requires companies to supply their employees with a safe workplace. Among the other 99%, the main stumbling block seems to be a widespread assumption that violence is more or less random--that there's no way to predict when a troubled worker will suddenly snap. But according to Doug Kane, a former FBI agent who runs a security and training firm called Risk Control Strategies, based in New York City, that's just not so. "People don't suddenly 'just go crazy.' Workplace violence is one of the few types of violent behavior that follows a clear pattern," says Kane. "It is never spontaneous and almost always avoidable."

Unfortunately most managers, including human resources professionals, have never been trained to recognize the warning signs, Kane says. Strangely enough, people who commit violent acts at work seem compelled to announce their intentions beforehand. "It starts with a pattern of threats and intimidation that escalates over the course of six months to a year," says Kane. In one company that called on Kane for help, an employee began by subjecting a co-worker to mild verbal abuse, then moved on to keying his car and breaking windows at his house before finally assaulting him with a deadly weapon. "It was all part of the same pattern," Kane recalls, "but the company didn't spot it because it was viewing each act of aggression as an isolated incident." At Lockheed Martin people who worked alongside Doug Williams heard him make so many violent threats that some of them, including one he later killed, were afraid to come to the plant in the morning.

To be effective, an antiviolence policy has to educate everyone about the possible consequences of such talk--and encourage employees to report threatening behavior long before it erupts into assault or even bloodshed. Companies need to train managers to keep their eyes and ears open and respond appropriately to violations, which may include anything from a concerned chat to immediate dismissal. "It's ironic that every company in the U.S. now has a policy against sexual harassment, including awareness of what it is and mechanisms for dealing with it," says Kane. "But nobody dies from sexual harassment."

Since the Meridian disaster, Lockheed Martin has formed a task force on workplace violence that gave rise to a zero-tolerance policy (violators can be fired) for hostile or intimidating speech or action. Training for managers has been stepped up too. The 99% of companies with no such safeguards in place might want to consider following suit. "The biggest mistake employers make is denial. They tell themselves, 'It won't happen here,' " says Kane. "But violence can and does happen anywhere." Maybe, along with our national war on terror, it's time for a company-by-company campaign against the enemy within.

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