Scenes of police in body armour shooting workers had not been seen in South Africa since the apartheid era and they shocked the world when the massacre took place at Lonmin's Marikana platinum mine.
It was an uncomfortable stain on the country's record in addressing inequality. But not a surprise for some analysts.
"Between 60 to 65 percent of South Africa's wealth is concentrated in the hands of just 10 percent of the population," Nick Branson, a senior researcher at the London-based Africa Research Institute, told RFI on Monday.
"Now, 20-25 years after apartheid that's pretty untenable, really. And this level of inequality, whether it's been mirrored in other neighbouring countries in Namibia or Zimbabwe, eventually something's got to give."
The protesters who were shot were demanding a pay increase to 12,500 rand (950 euros) a month, instead of the 4,000 rand (350 euros) they earned for potentially dangerous and stiflingly hot conditions underground.
A drop in the ocean compared to the earnings of the British mining company, Lonmin, which was reporting annual profits well over 170 million euros.
"We don't see any major change in terms of what was happening in 2012 and what's happening now," Eric Gcilitshana, the national organising secretary of South Africa's dominant National Union of Mineworkers (NUM) told RFI.
Rights groups like Amnesty International are unanimous on this point. In a new report, they argue that Lonmin has failed to improve the "appalling" living conditions for thousands of workers, despite its promises.
Unions in turf war
Workers, feeling let down by NUM, took matters into their own hands by directly going to Lonmin management offices on 10 August 2012 but were turned back by a Lonmin official who fetched an NUM representative.
Some went on to join the Association of Mineworkers and Construction Union, AMCU, that broke away from NUM accusing it of collusion with mine bosses and selling out miners.
"We were not collaborating with Lonmin employers," insists Gcilitshana.
"NUM was at its mobilisation stage ... we still saw the employer as a capitalist enemy to working class but our level of understanding with Lonmin employers was more mature at that point in time."
Yet the fact that the NUM allegedly accepted wage settlements that tied workers into years of meagre increases, didn't help their support base, which has fallen from 60 to six percent in four years.
The disaffection of mineworkers spawned the creation of parties like the Economic Freedom Fighters (EFF) led by Julius Malema.
"They were able to tap into grievances among communities that just feels the ANC has left them behind," argues Branson.
"As far as the ANC is concerned, the landless, disaffected migrant workers in the north-west are not worth listening to and their grievances are not a priority, shall we say."
Ultimately unions considered close to the ruling African National Congress party, lost their credibility in the Marikana massare.
Labour law reform proposed
Since 2012 there have been plans to reform the labour movement and its collective bargaining power.
"There are plans to review section 21 of Labour Act, which allows trade unions of about 10 percent membership to have access and facilities to recruit more members," says Gcilitshana.
"Regardless of that, the threshold to hold organisational rights remains 40-45 percent."
Whether or not those reforms go through, what the Marikana massacre anniversary reveals is that some workers no longer feel represented by long-established trade unions.