STOCKHOLM, SWEDEN - APRIL 09: The Swedish royal family including King Carl XVI Gustaf of Sweden attend the city of Stockholm's official ceremony for the victims of the recent terrorist attack on April 10, 2017 in Stockholm, Sweden. Four people died and fifteen were injured after a hijacked truck crashed into the front of Ahlens department store in Stockholm on April 7, 2017. (Photo by Michael Campanella/Getty Images)
STOCKHOLM, SWEDEN - APRIL 09: King Carl XVI Gustaf of Sweden and Queen Silvia of Sweden leave the city of Stockholm's official ceremony for the victims of the recent terrorist attack on April 10, 2017 in Stockholm, Sweden. Four people died and fifteen were injured after a hijacked truck crashed into the front of Ahlens department store in Stockholm on April 7, 2017. (Photo by Michael Campanella/Getty Images)
STOCKHOLM, SWEDEN - APRIL 09: Crown Princess Victoria of Sweden and Prince Daniel of Sweden leave the city of Stockholm's official ceremony for the victims of the recent terrorist attack on April 10, 2017 in Stockholm, Sweden. Four people died and fifteen were injured after a hijacked truck crashed into the front of Ahlens department store in Stockholm on April 7, 2017. (Photo by Michael Campanella/Getty Images)
STOCKHOLM, SWEDEN - APRIL 09: Princess Sofia and Prince Carl Phillip of Sweden leave the city of Stockholm's official ceremony for the victims of the recent terrorist attack on April 10, 2017 in Stockholm, Sweden. Four people died and fifteen were injured after a hijacked truck crashed into the front of Ahlens department store in Stockholm on April 7, 2017. (Photo by Michael Campanella/Getty Images)
STOCKHOLM, SWEDEN - APRIL 09: Princess Sofia and Prince Carl Phillip of Sweden attend the city of Stockholm's official ceremony for the victims of the recent terrorist attack on April 10, 2017 in Stockholm, Sweden. Four people died and fifteen were injured after a hijacked truck crashed into the front of Ahlens department store in Stockholm on April 7, 2017. (Photo by Michael Campanella/Getty Images)
