The Kenyan Muslims were of course taking a chance when they showed a united front. The attackers could have simply gunned down all passengers but they did not.
Who is al-Shabab?
Al-Shabab is akin to the youth movement of terrorism in Somalia; al-Shabab means 'The Youth' in Arabic.
They have begun carrying out raids in neighbouring Kenya a country which was and maybe still is a popular tourist destination.
Grenade attacks carried out by al-Shabab in Kenya will not aid tourism; if tourism dies poverty in Kenya will deepen.
In April 2015 "at least 147 people died when gunmen stormed the [Garissa] university at dawn and targeted Christian students. They were also responsible for the attack on Nairobi's Westgate shopping centre in 2013 where at least 68 people were killed.
According to the BBC al-Shabab "emerged as the radical youth wing of Somalia's now-defunct Union of Islamic Courts, which controlled Mogadishu in 2006, before being forced out by Ethiopian forces. There are numerous reports of foreign jihadists going to Somalia to help al-Shabab, from neighbouring countries, as well as the US and Europe. It is banned as a terrorist group by both the US and the UK and is believed to have between 7,000 and 9,000 fighters."
In other words yet another group of radicalised individuals with hate in their hearts for at least some citizens of the world.
Somalia is a poor country; around half the population of Somalia live in poverty. Natural disasters have played a part in the country's woes but civil unrest, conflict and a lack of cohesive government shorten the lifespan of local people and continue the cycle of poverty.
Some young men occupy themselves with al-Shabab.