The City of Houston Mayor’s Office of Public Safety and Homeland Security has produced a YouTube video describing what you should do if a shooter enters your work place or some other public space.  Always have a plan, says the video.  Be aware of your surroundings.  

The video, called "Ride, Hide, Fight" says if a shooter enters, first try to leave.  Leave your belongings behind.  Encourage others to leave with you, but do not wait for indecision.  Call 911. 

If you cannot get out safely, hide.  Act quickly and quietly.  Turn out lights.  Lock doors.  Remain quiet and as calm as possible.  Silence cell phones. 

As a last resort, if your life is at risk, fight.  Act with physical aggression.  Improvise weapons.  Commit to taking down the shooter no matter what.  Act aggressively. 

Keep in mind, says the video, that victims are generally random.  The event will evolve quickly. Expect the unexpected. 

Let’s hope no one ever needs this information.  But, be prepared.  The Mayor of Houston says the video was in production prior to the Aurora, Colorado incident.  But, her office released it early after the Colorado shooting.  See video.  See CBS News report