What To Do In The Event Of A Bomb Blast

"Soldier Takes Cover From Grenade"

Given that the risk of terrorist bombings in Europe and, potentially, the United States, it behooves us to become familiar with basic methods of protecting yourself from the blast and shrapnel. While shrapnel presents an obvious danger, the risks of overpressure from the blast can actually be more dangerous. Accounts from soldiers subject to artillery bombardment often mention having the breath knocked out of them, ruptured eardrums, and bleeding eyes, just from the pressure wave created from the blast. This over-pressure can rupture your eardrums or lungs if you are close enough to the blast. In addition, the blast can create secondary shrapnel effects from shards of glass, broken pieces of concrete or rock, shattered woods, and so on, and their may be resulting fires. The air may be filled with dust, smoke and/or gas from ruptured gas lines.

Grenade explosions produce an upside-down cone with an approximately 6 to 7 yard kill zone. Obviously, if there is time, it is best to seek cover. However, if cover is not available within 3 steps, you should dive to the ground as described below.

With that in mind, typical points and tips made for protecting yourself from a blast are:

In the event of an explosion, if you are outdoors:

1. Immediately open your mouth ("I am a fish") and, if possible, scream. This helps with relieving pressure differences caused by the passing shock wave and your lungs and/or inside your ears.
2. Seek cover from the explosion by:
1. Running away from the explosion, putting as many solid objects (walls, cars, etc.) between you and the explosion as possible or seek a hole or other feature that allows you to get below the surface of the ground; or,
2. If there is no cover or time to reach cover, drop to the ground with your mouth open (see above), your head pointed away from the explosive/blast, your legs together with the soles of your shoes toward the explosive/blast, your elbows to the sides of your torso (rib cage) with your hands over your ears, and keep your eyes closed. As discussed, opening your mouth will protect you against the effects of over-pressure. Covering your ears with your hands will further protect your ears. The legs together with your feet toward the source of the explosions will further protect against shrapnel or debris striking vital areas of the body. 
3. After the explosion, avoid choke points or dead-ends, crowds, unattended vehicles, and public transportation: these may be targets (or sources) of secondary attacks.
4. Seek medical attention, if necessary.

If you are indoors;

1. Open mouth and drop to the ground/floor as described above.
2. If there is time to flee the scene, get as many walls between you and the explosion as possible.
3. Find emergency exits and try to get out of the structure.
4. Follow the directions of emergency personnel.
5. Move away from streets or routes that will be used by emergency personnel or other evacuating the building.
6. Be aware of possible secondary explosives or explosions; avoid lighting matches or using lighters as there may be gas leaks. Avoid crowds, unattended vehicles, and public transportation.
7. Seek medical attention, if necessary.

Sources:

• Emerson, Clint. 100 Deadly Skills, p. 184 (2015).
• Haigh, Tony. Surviving Terrorism, pp. 70-71 (2008).
• Usmani, Zeeshan, "What to do if you are caught in a bomb blast,"The Express Tribune (Aug. 19, 2012). Experience from the civilian point of view.
• Wagner, Jim, "Surviving a Grenade Attack," Black Belt Magazine (March 2002).