In South Africa, the violence started within minutes of the police statement: a Mozambican labourer in Mpumalanga Province had been arrested on suspicion of being involved in the murder of Lesedi Motlantshe. Across the country there were reports of attacks on foreigners. It didn’t matter where they came from: an exotic accent was enough. In barely forty-eight hours, parts of South Africa began to look like a war zone.

‘Let them cook,’ the man shouted, as the fire-fighters tried to muscle their way through the crowd that had gathered around the western entrance to Ponte City. Above the screaming heads, a window on the fifth floor of the building belched thick black smoke. Occasionally the wind would clear it, revealing the hungry flames probing for new material to devour. From several other windows, occupants of the building leaned out, pleading for help. But their fear-filled cries were drowned in the noise below, the wailing police sirens, the deep-throated mechanical murmur of the fire-engine pumps and, above it all, the taunts of the crowd flinging their filthy curses like bloodthirsty spectators waiting for the kill in a gladiatorial contest.

‘We don’t want foreign rats in South Africa!’ a woman shouted.

Immediately, as if on cue, those around her took up the chant: ‘The rats must go! The rats must be killed!’

Much higher, from the crown of Ponte City, there was a curling, twisting stream of smoke. On the ground, a section of the crowd suddenly surged in one direction, no one really knowing what they were looking for but all of them scenting spilled blood. The police had cleared a space around a twisted body on the pavement.

‘Fucking Mozambican was trying to run,’ someone said, as if that was explanation enough as to why the man lay lifeless where he’d fallen.

‘The place is full of them,’ another said, adding, ‘You can smell them.’

The fifty-four-storey doughnut-shaped Ponte City, which dominated the Johannesburg skyline, had once been one of the most desirable places to live. Built in the mid-seventies, the tallest residential building on the continent, it stood tall and proud, like a middle-fingered rebuke to those who hoped apartheid’s foundations were crumbling. But for all its architectural precociousness, the Ponte was left isolated in the eighties as the Group Areas Act, which strictly assigned different parts of the city to different races, began to lose its force and the complexion of downtown Johannesburg began to change.

The adventurous white city-dwellers, who had revelled in their fast-lane lives, found a new enthusiasm for the mundane charms of the suburbs. As the white tide retreated, it was replaced by a swirling torrent of black people, many of them from outside the country’s border. Africa, in all its spectacular colour and chaos, lashed the Ponte building, like a wave crashing into a cliff. It didn’t stand a chance.