Dateline | November 22, 2013
>> reporter: walton was awakened by a call telling him his family was trapped in the westgate mall , pinned down by gunfire. he had been on his computer all morning checking for updates. then suddenly he received a facebook message from a friend with a feze frame, video, and there in the bottom right hand corner was an unmistakable sight. his two sons, alive. and outside the mall.
>> my twsons standing with my business partner . a very big, noticeable man. paul weaver raced down to the mall area and confirmed the picture was real. the boys were out.
>> just seeing them, i mean, i don't think there has any bigger hugs in the world. it was joy, at the same time, just seeing the anguish in their face. and blez, we sat on the floor and he just laid his head down all the emotions coming through him. one of the greatest moments and saddest moments at the same time.
>> reporter: a joyful moment for phillip knowing hiboys were finally safe. but too brief. he knew his wife and three young daughters were still trapped in that mal the walton boys, 14-year-old blez and 10-year-old ian had endured 3 1/2 hours in the most dangerous area. in the department store where terrorists gunned down innocent victims, terrifying for any one but especially for two boys separated from their mother. this is blez walton . it was difficult for him to recount the story of what happened to him and his brother. buhe wanted to tell it, starting from the beginning. the two brothers had just paid and were standing in the checkout line when they saw somethg strange.
>> what's the first thing you hear or see that is weird?
>> everybody looks to -- to the main entrance. and, we all look as well. everybody, in nakuma, and then a loud sound happens. three people go flying. that's when people realize what is going on. and they run.
>> reporter: three people going flying into the air.
>> just fell backwards. just went -- it was scary.
>> reporter: did you think it was a bomb or something?
>> i thought it was a bomb. en i heard the two gunfire sounds. i knew it wasn't just a bomb. it was something else.
>> reporter: he knew he had to protect himself. more than that he knew he was response bum ible for his younger brother .
>> reporter: you grabbed your brother, fast as you could.
>> just ran.
>> reporter: were you pushing him?
>> reporter: you didn't want him to seep it? that's hard, that would be hard for me. hard for a grownup.
>> yeah. at 14, it is pretty darn hd.
>> it really is.
>> reporter: blez clutching his brother, ian race add way from the gunfire with just one thought.
>> i just thought ian first. save him. me second.
>> reporter: you headed towards the back of the store.
>> other people at the time were rushing back. we followed the crowd.
>> reporter: they made it to a storeroom at the back of the store, others were hiding there too including an american mother with her own kids. without katherine there to comfort them, the boys stayed with that mother. blez hoped they were far enough away from the gun toting terrorists but they weren't. surveillance video shows the terrorists made it all the way to the back, hunting for more victims. but this wise 14-year-old did something ingenious.
>> i finally pulled ian aside, sat him down on a thing of flour, one by one, meters of flour on all sides of him.
>> reporter: like a barricade of flour bags?
>> yeah, pulled toilet paper on top of our heads so nobody could see us.
>> reporter: why did you need to be hid sndenhidden.
>> we didn't know if people would walk back and look for us. we pulled out all stops.
>> reporter: 10-year-old ian walton remembers how scared he was. did you see any of the bad guys ?
>> no. but it did seem like some one closed the gate to where we were and tryingow to shoot through it and throw grenades to blow it up. they never got through.
>> reporter: you heard a lot of loud sounds?
>> reporter: yikes you. said you were back there, how long?
>> 3 1/2 hours.
>> reporter: you thought about it a little bit, yeah? when you were there, i know if it were me i would have been really, really scared.
>> were you pretty, pretty scared? all my brother and me did was just pray for our family and just laid there.
>> reporter: they lay there and stened.
>> every once in a while we would hear gunfire, grenade sounds, and at one point, these people came and said "we are the police. it is okay."
>> reporter: the gunfire the walton boys had been hearing briefly paused. the voices identifying themselves as police were encouraging people to come out. around him, blez heard pple start moving.
>> they walked out. 15 second later, you heard a lot of machine gunfire, for 30 second. then it was just quiet.
>> reporter: you think it s the bad guys luring them out. you did right ing by staying where you were?
>> yeah, the lady we were with. told us what to do every step of the way. without her, i don't think, i think me and my brother would have gone out with the crowd. thanks to her we are still alive.
>> reporter: the walton boys were holed up in the back room when eventually police were able to break down the door and get people out. this security camera shows the chaos in the crowd after being released. look closely, there is blez in his red shirt . ian with his backpack. free, after 3 1/2 hours of being trapped. relief washed over phillip walton when he saw his boys in the image his friend sent him. at least his sons were okay.
>> i remember thinking at that time. at least i won't be alone. i remember thinking, however horrific this day is, at least the boys and i will have each other if it, if it turns out, worse than, we would -- than we would hope or imagine.
>> reporter: his wife katherine was stiltrapped under that tiny table with her three girls. and now, things were looking worse. a man with a gun was headed their way.