You’re at your desk at work one day, watching the seconds and the minutes ticking ever so slowly by, longing for the moment when you can get up and head for the parking lot and freedom, when suddenly . . . uh oh.

In through the office door comes the guy who got fired a month ago, the guy you were happy to see let go, the guy about whom you and your coworkers said things like, “I wouldn’t be surprised if he came back with a gun some day.”

Some day is here, and so is the guy, and so is the gun.

What do you do now?

Even for those who are careful planners, the people who plot out their days down to the finest detail and consider options for every conceivable turn of events, such a contingency must seem too remote to consider.  But what if?

A recent story in the New York Times asks that very question, and reports that opinions on the answer have changed.  “The speed and deadliness of recent high-profile shootings,” says the Times, “have prompted police departments to recommend fleeing, hiding or fighting in the event of a mass attack, instead of remaining passive and waiting for help.”

In light of such recent horrors as the massacres in Newtown, Conn., and Aurora, Colo., this advice may seem obvious enough.  But as the story notes, it represents a shift in thinking among police researchers who once counseled people to call 911 and wait for help to arrive rather than run, hide, or fight in the event of an attack.

A close examination of mass shooting incidents revealed that the chances of survival increased when potential victims took steps to resist an attack by a gunman.  The research, conducted at Texas State University, looked at 84 such incidents and found the rate of survival was higher in those cases where people fought or obstructed the attacker.  For example, researchers noted that in the Virginia Tech University massacre that took place six years ago this week, in two classrooms where students and teachers tried to hide or play dead after the assailant entered, nearly all were shot and most died.  In another classroom, the teacher held the door shut long enough for most of his students to jump out a window.  The teacher was shot through the door and killed, as was one student, but the others survived.  In a third classroom, the teacher and students blocked the door with a heavy desk, preventing the gunman from entering.  Everyone in that room survived.

The most important message emerging from the study is this: in the event of a mass shooting, the police may not arrive until it’s over, as was the case in about half the incidents examined.  The average police response time in the 84 shootings was three minutes, which may seem fast until one considers how much carnage a committed and well-armed gunman can bring down on a school, office, or shopping mall in three minutes.

Public safety officials in Houston have produced a video that instructs people to take action if they find themselves faced with a mass shooter.  Filmed in an office building, the video depicts a scenario typical of a workplace shooting.  People are going about their business when suddenly a man walks in, pulls a shotgun from a backpack, and starts shooting.  The video advocates running as the preferable option if a safe escape route is available, and barricading the door and hiding if one is not.  As a last resort, the video recommends using any kind of improvised weapon available and taking the attack to the attacker, an option I couldn’t endorse more strongly.  As the valiant passengers of United Flight 93 demonstrated on Sept. 11, 2001, if you’re going to be killed anyway, better to put up a fight and make the bastards work for it.