It's dramatic video showing a massacre in an office building.
Survivors fleeing for their lives, terrified workers barricading themselves in their offices, and a heroic few preparing to fight the crazed killer.
It's not a tragedy caught on tape. It's a graphic, just-released public service video produced by the Houston, Texas mayor's office.
In the wake of the massacres in a Colorado movie theater and in a Milwaukee area Sikh temple, it's in-demand by cities and businesses across America.
"Run, hide, fight," states the video.
The video advises anyone caught in a mass shooting to first, run if possible.
If evacuation is not possible, the next best option is to hide until SWAT teams some to the rescue.
But the video's most controversial advice is—as a last resort—stand and fight.
"Commit to taking the shooter down. No matter what," says the video.
INSIDE EDITION showed the video to security expert Steve Kardian.
"If you have no means of escape and you believe that person is about to shoot you, you've got to fight back or you are going to die," said Kardian.
Meanwhile, we're learning more of the drama and chaos at that Sikh temple in Wisconsin from just-released police radio dispatches.
"Ambulance up! Subject down! Four officers are down!" said one radio dispatch.
"Could somebody try to make contact inside and see what the situation is in there, and if it looks like there is another shooter?" said another.
"We have one officer shot!" said yet another.
Police say the killer, Wade Michael Page, was a white supremacist discharged from the U.S. Military in 1998. He played in a neo-Nazi rock band called End Apathy. He was shot dead by police.