(CNN) — It’s a decision you have to make in a second, and one that might save your life for a shooting: run away or play dead?
The answer, according to the new direction of the UK National Security Counter Terrorism Office (NACTSO) by its initials in English), is to run or hide behind “solid bricks” or “heavily reinforced walls”.
Which might sound pretty intuitive. Except, for some people who have unfortunately ended up in the middle of a firefight, it’s not that obvious.
This guide was published following the November 2015 attacks in Paris in which some reportedly lay down and stood still while terrorists fired indiscriminately into the crowd.
If you find yourself in the middle of an attack, the report advises following three principles:
1) Corre: Identify the safest route and escape if you can. Insist that others go with you and leave your belongings behind.
2) Hide: If you can’t run, then hide. Try to find a safe hiding place, ideally behind heavily reinforced walls. And remember that bullets can go through glass, wood, brick and metal. Also make sure cell phones are on silent.
3) Account: Once you can, call the police and give them as much information as possible: where are the suspects and what do they look like? How many people are left inside the building?
Knowing what to do might save your life and the lives of others.
Publisher’s note: This text was initially published in November 2015.