Dismembered bodies, blood stains, abandoned baby strollers in the street: Witnesses still in shock recounted Saturday how a barreling truck transformed a bustling Stockholm pedestrian street into a scene of horror.
"I've seen dead people, and I've seen accidents before, but this ..." Margareta Larsson, 67, is an experienced nurse but she has to pause, her voice cracking with emotion.
"I don't want to describe what I saw ... I mean, the body was so torn apart."
In what Swedish authorities have described as a "terror attack", a driver in a stolen truck tore more than 500 metres (550 yards) down the Drottninggatan pedestrian street on Friday afternoon, mowing down people before finally slamming into the facade of the Ahlens department store.
Four people were killed and 15 injured.
Police have arrested a suspect they believe to be the driver, identified only as a 39-year-old Uzbek man previously known to Swedish intelligence officials.
Larsson was heading towards the T-centralen central station with a friend when they saw the truck bolt through a crossing "at an immensely high speed."
"We immediately understood that there was something wrong because you don't drive like that in a crowded city on a Friday afternoon," she told AFP. "My friend grabbed me and said: 'This is a terror attack, it has come to us'."
"There were of course a lot of people ... A few screamed and were in anguish but there were also quite a few who were standing there, like us. We didn't scream, we didn't shout, we didn't run, because what we saw was so unbelievable. People were in shock," she said.
Rasmus Myrvalder, a 27-year-old in Stockholm to attend a concert, first thought the truck was having technical problems as it raced down the street -- before realising the scary truth.
"He kept switching into higher gear, he was zigzagging and mowing down all the people," he told Swedish public television SVT. "All he wanted was to kill as many as possible."
"I saw people without arms, without legs," he recalled, tears welling in his eyes.
His efforts were in vain.
"A security guard came up and said we had to leave, there could be other attacks," he told SVT. "I felt an enormous need to close this person's eyes, so I did that and then we tried to get out of there."
A doctor at Karolinska Hospital, Marie Smedberg, got off the metro and rushed to the scene after reading what was happening on her smartphone.
"You could see stuff still lying on the ground. There were also dead people, covered, lying on the ground. And blood every now and then. And strollers that were left on the street," she told AFP.
"And then there were a lot of people in all the stores and all the cafes along Drottninggatan who were told to stay inside. Shocked and crying people..."
Yet she saw a small glimmer of goodness on what was otherwise a very dark day: she was "very impressed" by the emergency crews' quick response.
"In 25 minutes, everything was cleared and everyone was taken care of."