They are out there: disturbed people seeking 1 day of fame and hoping to achieve it by spreading death and destruction. In America, it has been reported that almost all of these individuals were taking medication, with Ritalin mentioned remarkably often. But that knowledge is of no help if you find yourself in the same place as one of them.
Get used to looking for escape routes wherever you are. Not only the main entrance but also emergency exits, entrance for personnel or suppliers, etc.
If you ever have to escape, do so. Do not linger in the car park, and certainly do not try to retrieve your coat from the cloakroom. Your coat and car can wait. Bear in mind the possibility of a 2nd attack.
Only once you're safe will you call the police. If it is clear that they have already been called, then of course you do not. They'll be busy enough.
Should you always flee? Yes, except if you are in a position to stop the attacker. Use any object that can serve as a weapon: a bottle, a frozen chicken or whatever is available, as long as it lets you deliver a substantial blow.
“I am not taking that risk,” you say. “I will end up in prison too. This is the Netherlands, after all.”
Hmm, well...
And if you cannot escape? Take cover.
There are two kinds of protection: concealment and cover.
Concealment hides you from view and does nothing more.
Cover both hides you from view and offers protection against bullets, shell fragments and similar hazards.
Find a concrete planter, column, around the corner in a corridor, under a table or desk. Anything's better than in plain sight.
How can you arm yourself in everyday life? Your options are very limited. Our legislation hardly permits carrying a weapon as a precaution. The legislature has given the police a monopoly on the use of force. If you have ever called them, you know they do not always arrive immediately. If something serious is happening, they may also wait until enough officers have assembled.
The only real option is a small light with a very serrated edge around the LED unit, which can cause considerable pain. Some models have a clip, which helps keep the light in a useful position. If you first have to rummage in your pockets, or worse, a shoulder bag, you are too late. Keep it within easy reach. And yes, it works in daylight too.
Another advantage of a powerful light is that it lets you see a little farther through smoke. Stay low, where the smoke is less dense, and locate other people and an escape route.