An image grab taken from AFP TV shows two children and a woman taking cover behind a bar inside a shopping mall following an attack by masked gunmen in Nairobi.
Nairobi's Westgate shopping mall, part Israeli-owned and often crowded with well-to-do Kenyans, expatriates, diplomats and UN workers, has long been seen as a soft target for Islamic militants.
The sprawling multi-storey complex, which opened in 2007, is known for its shops carrying trendy foreign brands as well as its friendly cafes and restaurants. Their terraces, however, are adjacent to a road along which cars can pass without security checks.
Entering the mall is normally easy, involving a cursory body check, sometimes with a small metal detector - but there were no walk-through security scanners of the sort upmarket hotels have installed since the Shebab first started threatening to avenge the entry of Kenyan troops into Somalia.
Cars entering the mall - which also has a multi-screen cinema, a food hall and other services such as banks, not to mention a casino - are also only given a quick check by private security guards.
"Given Westgate's strategic nature it's certainly a target for terrorists," said Emmanuel Kisiangani, a Nairobi-based analyst with South Africa's Institute for Security Studies.
"Terrorism is all about maximising impact, and as Westgate is frequented by the rich and by foreigners, it makes a good target."
Alerts issued intermittently by foreign embassies over the past two years have regularly listed Nairobi's shopping malls as possible targets - but the crowds have not stayed away.
Israeli interests in Kenya have come under attack before. In November 2002 there were two simultaneous attacks in the Mombasa area. A missile targeted an Israeli charter flight as it took off from the port city's airport, but missed.
At the same time a car packed with explosives smashed into the Paradise hotel, the only Israeli-owned hotel in the Mombasa area, as Israeli tourists were checking in. Ten Kenyans and three Israelis died.
Al-Qaeda's east Africa cell was blamed for the attack, which came four years after the bombing of the US embassy in Nairobi that left 213 people dead and thousands wounded.
According to a Western intelligence source, Westgate was always an attack waiting to happen.
"It was only a question of time until a mall was targeted," said the source.
When Kenya sent tanks and troops across the border into Somalia in 2011, it sparked a series of attacks around the coastal city of Mombasa, in the areas bordering on Somalia and in Nairobi, but until Saturday the attacks in the capital, mostly attributed to Shebab sympathisers, have tended to be small-scale incidents at small bars and local shops.
With the Westgate attack, Shebab "struck as a way of sending a message they are still relevant," said the ISS's Kisiangani.
In the wake of the Westgate attack, several other upmarket shopping centres in Nairobi closed as a protective measure, as did most outlets of the capital's leading hypermarket chain Nakumatt.
"In one sense Westgate Mall is the perfect target," said Stig Jarle Hansen, a Somalia specialist and author of "Al Shabaab in Somalia: The History and Ideology of a Militant Islamist Group".
"You meet expatriates there, you meet the Kenyan elite -- there are a lot of expats from the UN and members of the local elite (and) the security there is not good at all," he added.
"By making the attack so visible it will hit Kenya where it hurts the most by hitting the tourism sector. Kenya managed to survive the financial crisis quite well but this will hit them."