Cecilia Rosén had been at an event with colleagues and was on the way toward Berlin's Zoo on Monday evening. She had just walked through the Christmas market at Breitscheidplatz. She was standing at a crossing when she saw the lorry coming.
The 28-year-old tells Swedish Radio's P3 programme Morgonpasset that it was coming towards her.
"I saw the lorry drive toward me. I thought oh my god it must turn soon and then in the next second it thunders into the Christmas market on my left side. Some started to shout, 'run away'.
She ran into a large cinema nearby.
"It was surreal. I was completely in panic, shaking hands, I'm hyperventilating, but when I got there it was completely quiet and nobody knew what had happened.
Today, she feels that the mood in Berlin has been calm.
"At first I was afraid to take the subway, I thought that someone had planned the next attack there. But I took myself down and it was completely calm," Cecilia Rosén tells P3 .
The lorry ploughed into the Christmas market at an estimated speed of 64 km/h travelling for 80 metres before coming to a stop.
At least 12 people have died, and 48 are injured - according to the German interior minister.