UNDATED (WIFR) -- The mayor of Houston, Texas and the Department of Homeland Security have released a new video that tells people what they should do if they're in a public place when a shooter opens fire.

The video cost about $200,000 to produce and was made before the shootings at an Aurora, Colorado movie theater. Recent events like the Colorado massacre convinced the mayor to release the video sooner than planned.

Much like the "stop, drop, and roll" mantra of firefighters, the video teaches people to run, hide, and fight - if necessary.

If you can't get out of the building, you should lock yourself in a room and turn off the lights.

On YouTube, the video has gotten more than a half million hits in the last two weeks. Houston says it's gotten multiple requests from law enforcement around the country to use the video for training.