A bomb exploded Tuesday on a busy street in Mogadishu, Somalia killing 70 people and injuring many more.
Many of the victims were students who had gathered near a government building to register for scholarships to study in Turkey.
The al-Qaeda affiliated group al-Shabab claimed responsibility.
It is always difficult to imagine what could motivate an individual, whether in Somalia or Afghanistan or anywhere to carry out such a horrific attack.
Author Ken Ballen has tried to grapple with the logic.
He interviewed more than a hundred extremists for his new book "Terrorists in Love: The Real Lives of Islamic Radicals."
Among those he profiles is a star-crossed couple.