The ninth-graders at Östra skolan in Hudiksvall had during the day made a study visit on the risk day.
After the tour, the students would be allowed to spend a few hours free in Stockholm before returning home.
Hannah Berglin and her friends were then inside a store on Drottninggatan.
- There were so many loud noises that were continuous so it was impossible to understand where they came from, so everyone in the store turns around and looks out.
And then everything goes so fast, so does the truck then, says Hannah Berglin.
Still affected by the event
Today Hannah Berglin lives in Uppsala where she is studying to be a veterinarian.
Even today, she can be reminded of the event on Drottninggatan 2017.
- I did not understand it at first, but afterwards I have become incredibly much more sensitive to loud noises.
It is hardly the case that I can wear the vacuum cleaner at the highest volume because I think it is so uncomfortable with such hurried sounds, says Hannah Berglin.
Watch Hannah Berglin tell more about her experience from the terrorist attack in the clip above.