PHOENIX - The FBI's Phoenix office says if you find yourself in a situations involving an active shooter, the best thing you can do are run, hid and fight.

It's a mantra becoming more and more prevalent as instances of mass shootings have happened with terrifying frequency.

The experts stress that everyone should trust their instincts and if something doesn't feel right, don't wait for others to react.

The massacre at Columbine High School in 1999 forced law enforcement agencies to take a look at how to handle those types of situations, enabling local law enforcement to act on their own accord instead of waiting for a SWAT team to arrive.

Statistically, according to the FBI, shooters tend to cease fire when law enforcement arrive, which is why alerting authorities is key to helping gain control of the situation.

The experts say if you find yourself in an active shooter situation, the best advice is to run away from the threat and get to safety. If that's not an option, the next best thing to do is hide. Barricading a door and turning out the lights is one way to increase your safety. If the shooter cannot gain entry, it's less likely anyone will be harmed. The last option is to fight. This action should only come when someone's life is in imminent danger. Stopping the threat entirely can not only spare your life, but the lives of many others.

For more information visit the FBI's website.