What was the impact of the Westgate attack on Kenya's Somali community?

It was a shocking attack which still has implications today: in September 2013 fighters from the Somalia-based al-Shabab militant group burst into the Westgate mall in the Kenyan capital, Nairobi – taking control of the building for the next four days. At the end of the siege, 67 people were dead, with almost 200 wounded. So what impact did it have on relationships between different Kenyan communities? And why has it led many Somalis in Kenya to rethink their culture of hospitality?