Zachary Yach is an 18-year-old South African whose family recently moved to Kenya. He told the BBC's Will Ross how he defied his dad's orders to leave a restaurant where he was trapped for two and a half hours during the Westgate attack:
My sister, my mum and I had just come from a doctor's appointment and we headed off to a burger restaurant at Westgate for lunch.
We had just ordered our burgers and I was looking at the woman across from me and some pebbles, small rocks pieces of concrete were thrown at her and I was looking to see who was throwing the stuff.
Then a huge explosion really swept us off our feet - it was like a big gust of wind, like a sandstorm, things hitting your face and then a huge explosion which was ear piercing.
So we just dropped to the floor under the table, put our heads down and curled up for a good 20 or 30 minutes.
'A lot of dead bodies'
That was when a lot of grenades were being thrown and a lot of gunfire was happening and once that had subsided a bit, we put our heads up to see what was going on because we were completely clueless.
I saw one of the waiters - he was OK but he had a lot of blood coming from his head. Also, in the other corner of the restaurant, I looked and I saw a lot of dead bodies and I was really just praying for them to just wiggle a bit to see if they were OK and alive.
Thank God someone else moved his head and I pointed to him and asked him: "Are you OK?" you know with my thumbs up.
He had been shot in the arm so he managed to grab a knife and come towards us. He cut his T-shirt and tied it around - we helped him and tried to get him to keep pressure on.
In these kind of situations there's no time to think, you just react. So the first thing I thought of was just to make sure my family was OK and once they were fine, to help anyone else I could.
There were still bursts of gunfire.
The first time we saw the terrorists come out, I just said to my mum: "It's a scary thought but just play dead." So we did that but I kept an eye open to see what was going on and if they were coming into the restaurant.
We were there for a good two and a half hours under the table and about halfway into it, the police arrived with the army and they started heading up the steps of the main entrance.
There was a bit of a gun battle going on whilst we were still on the floor.
I managed to grab mum's phone and was SMS-ing my dad to tell him what was going on. But he didn't understand - he's like: "Just leave. Get up and walk out."
And I'm like: "No dad you don't understand, we're under the table and bombs are going off."
He's like: "OK, I'm coming down to get you, don't worry."
I said: "Dad, listen that's not what's going on."
So he turned on the news and saw what was happening.
Rescuers or gunmen?
It was incredibly scary. I had never realised how loud a gun was and how scary and threatening they are because every time a shot went off, you flinch and grab something.
The scariest part was the police and the army and the ambulances were there for a very long time but we never knew because there was a hedge between the road and our restaurant - we couldn't tell if the police were there because there were no sirens so we just stayed there all that time.
Then I looked across and saw what looked like a tactical team coming in the ArtCaffe entrance.
They were not wearing a uniform and they had handguns. At first I thought they were the terrorists but then they started checking the pulses of the bodies lying on the floor. They checked and did the finger-across-the-throat dead signal.
At this point I realised these guys were here to help us so I lifted up my hand and I whistled to say: "Come here we need help," so they opened a small gate and told us to crawl to them.
So I got my mum and sister to go first and then we went back to help the guy with the blood running from his head and the guy with the bullet wound in his arm. All five of us survived.
My dad was incredibly happy to see us.
I feel so sorry for the people younger than me who had to experience that - it is such a terrible thing to happen to anyone.
I'm just lucky that my family and I weren't taken hostage we were just observing it from under the table.
Even after surviving that I'm still very cautious. Even when I heard a door shut, I flinched.