I went shopping a week or so ago. It was pretty busy in the supermarket when the alarm started. A voice came over the loud speaker asking us to leave calmly and quietly. The message was repeated in English too. So we all walked to the exit calmly and quietly. I found somewhere to leave my trolly/cart, that I would remember, but most people were still pushing their shopping towards the exit.
After a few seconds everyone was coming back again. Then there was an announcement to say that the alert was a computer error. See how exciting life can be?