What happened in the Kenya mall attack?

The country is beginning three days of national mourning after the end of a four day siege at a Nairobi shopping centre. Tonight, we will piece together what took place in the attack carried out by the Islamist group Al-Shabab. We will hear from security experts, journalists who covered the story and people who found themselves caught up in the events.

(Picture credit: Kenya Defence Forces soldiers comb the rooftop of the Westgate shopping mall in Nairobi, REUTERS/Noor Khamis)