Denial is the first stage of coming to terms with the unthinkable.
In Westgate, a Kenyan mall oriented toward expats, terrorists separated Muslims from non-Muslims before killing them. The Muslims were allowed to go free if they could recite a Muslim prayer.
During the attack, Al Shabaab's Arabic Twitter account quoted the Koran, "Plant firmly our feet and give us victory over (Al-Kafireen) the disbelieving people." (Koran 2:250). The Kuffar, the non-Muslims of Westgate, included small children.