There is an incongruous feeling as you walk into the main entrance of Westgate Mall. Store owners and their helpers are wheeling out supermarket trollies filled with recovered goods and personal belongings.
FBI agents walk past engaged in casual conversation. Soldiers sit on mats, their weapons propped up by their sides. And all around them in what was once a family place there is evidence of death, murder and hatred.
There's a crunching under foot and with a glance down you see shards of glass in puddles of water mixed with cleaning fluid and blood.
"This way, hurry up," a shopkeeper says to a worker as she rushes past the information desk, carrying a bundle of files and a heavy handbag.
Ahead and to the left is Art Cafe. One of the first targets for the heavily armed attackers last Saturday.
Men with face masks are standing at the bar, the whiff of rotten food permeates with the scent of dead bodies even though they were removed days ago.
You think of how many people would have been sipping cappuccino and talking through their weekend plans when gunfire and grenades ended their lives.
A few floors up and the surreal unguided stroll takes in another distasteful reality. This Mall stood as a symbol of wealth and business success. But it also sat somewhat uncomfortably alongside Kenya's endemic poverty. Street hawkers are outside, beggars and shanty stall holders, along with small time thieves and street kids.
You have to add to that soldiers and police officers inside, some of whom consider a bribe a job benefit because of their low pay.
Like an air strike
But the looting that store owners blame on the security forces gives the sick air here another dimension.
The Rado swiss watch store's armoured glass seems to have been purposefully blasted to get access. So too the door into Barclays Bank nearby. And in front of a jewellery store empty display cases are spread out on the floor.
Millionaire's Casino on the top storey is the subject of one of many sidebar investigations because its safes have been peppered with bullets and prised open.
Such distractions go quickly with a view from the roof.
You look down to the rear of this complex and it looks like an air strike in Syria. A car park that's collapsed sending a deadly mass of rubble and vehicles into a crater. A mechanical digger is methodically clearing space. A group of white clad forensic figures are huddled around one car perched precariously on the top floor at the edge of the crater.
Back down the staircase on the ground floor it’s better not to go any further. Nakumatt was arguably the best supermarket in town. Now it's burned out and I'm told later that bodies are being recovered from the rubble beyond. You feel you are in a war zone.
With any attrocity on this scale there are questions and hindsight. They rapidly rush through your head as you prepare to leave.
How did the roof of part of this complex collapse? Was it the fire? Was it bombs detonated by the attackers? Was it the Kenya Defence Force using heavy weaponry when it was ordered to bring the macabre attack and hostage crisis to an end?
Or was it a combination of some of these possibilities?
And are the attackers all dead? Or did some escape?
Some of the investigators checking in while I was checking out are tasked to re-construct events. How many of those involved in the Westgate siege will reconstruct their lives is hard to imagine.
Later I speak to two men who are trying to deal with differing traumas.
Vincent Imbala walks like an old man but is in his 30s. He wears sunglasses all the time because of a watery eye, possibly damaged by the concrete dust where he works.
I suspect he may be shedding real tears behind his shades as he explains how he is searching for his twin brother, Joshua, a chef. He had been helping out in a children's cookery competition organised by the Asian community last Saturday.
"My brother was the only one educated in our family," he says in a soft tone.
"We looked up to him for everything. My heart is broken, my brother used to take care of me.
"Now he may be gone it hurts so much.
"Hearing the government say there are no more bodies in there leaves me wondering what to do next. But I fear the government may be witholding information."
Vincent tries to enter the Mall but is turned away by a soldier. He signs various forms and waits for a police Inspector who can’t help. He then heads for the bus station and a two hour dusty journey back to his small home in Naivasha. There are two young children there to look after. Joshua was their father. And he split with his wife. Now he is missing presumed dead. So Vincent will try to bring them up - one of many people who will never be the same as they were.
'Must never be forgiven'
Tall and handsome Abdul Haji tells me he will never feel the same either. In a selfless six hours, he rescued civilians and helped keep the attackers at bay with his pistol, the firearm he has to carry because his father was once a security minister.
He had just been reunited with an American family he rescued - the Waltons. A photograph of him coaxing four year old Portia Walton towards him is one of the most viewed pictures on the internet.
"It’s hard to describe how I feel now," he says.
"I went in there to find my brother and I did get him out with the help of other people. We were first responders really. I only had fourteen bullets for my gun."
Abdul understates his role in saving lives. And as a Kenyan-Somali Muslim, he can't find any apt words to address whatever motivation the killers of Westgate Mall possessed.
I ask him about all the questions that still lurk behind the security cordon around the mall.
One worries him more than any of the others:
"What everyone has been through is unimaginable," he says.
"If any of the killers have escaped then the security forces must never be forgiven."
But the unknowns outnumber the positives you can find in the aftermath of this attack. They are as disturbing as walking through Westgate Mall itself. And trying to comprehend the level of fear, suffering and human loss.
Follow Andrew Simmons on twitter: @simmjazeera