The cracks that suddenly appeared on Tuesday afternoon in the Rana Plaza building were large enough to send workers fleeing into the street.
They made the television news that night, but the building's owner, Mohammed Sohel Rana, told reporters the sudden appearance of cracks was “nothing serious”.
He did not say that police had ordered him to shut the factory. Nor did he mention that the top four floors of the building, in Savar, north of Dhaka, were constructed illegally without permits.
So on Wednesday morning, as workers gathered outside, unsure whether they could go in, factory officials appeared carrying megaphones, telling them the factory was open, and that their pay would be docked if they did not return to work.
Mr Rana was there again too. He reportedly told his workers of his factory: “It will stand for another 100 years”.
They went inside and began work, sitting at rows of sewing machines making jeans and shirts and jackets for the US and Europe.
Just after 9am, the eight-storey building collapsed without warning, all of it, save for the first floor, crashing in on itself.
In some parts of the wreckage, slabs of concrete that formed different floors can be seen crushed up against each other, with no space in between.
The death toll stood at 160 on Thursday, but it will rise. Most of the dead are women. Some of the bodies recovered appear to be those of children. Up to 1600 people, alive or dead, are believed still trapped inside.
Up to 6000 people worked in the building; it's estimated 2500 were inside when it fell.
Worker Nurul Islam was injured in the collapse.
“None of us wanted to go in. The bosses came after us with beating sticks. In the end we were forced to go in.”
Mr Rana has not been seen since the collapse, though police have filed charges against him and his father, as owners of the building.
Director of the industrial police Mostafizur Rahman said they disobeyed express orders to close.
“The industrial police had asked the owners of the factories to suspend operations after cracks were noticed in Rana Plaza. We had asked them to operate the factories only after a structural inspection by . . . engineers,” he said. “But the factories' owners ignored our directives and decided to reopen their units on Wednesday.”
Thursday was declared a national day of mourning by Prime Minister Sheikh Hasina. She has launched a formal investigation.
There may be political fallout for her from this collapse. Mr Rana is a well-known and influential convenor for her party, the Awami League.
Bangladesh's poor face some of the most miserable working conditions in the world. The country's garment industry is a $20 billion industry, second in volume only to China's. Five thousand factories in the country employ an estimated 3.2 million people.
But whereas the minimum wage in some Chinese provinces has grown to $200 a month, Bangladesh's remains stuck at 3000 taka, less than $37.
Most garment factory employees work a 12-hour shift, 30 days a month. They have no sick pay, holidays, parental entitlements or superannuation. If they do not, or cannot, come to work, they do not get paid.
The work is often lethally dangerous. Factories are shoddily-constructed and overcrowded, dimly-lit and with poor ventilation. Minor industrial accidents are common. So are major disasters.
In November a fire in the Tazreen Fashion factory in Dhaka killed 117 people, many of whom burned to death because the building had no emergency exits. Over the past decade, 700 workers have died in factory fires in Bangladesh.
Attempts to improve working conditions are met with hostility from factory owners, many of whom foster close links with government or who are active politicians themselves.
In April last year, Aminul Islam, a Bangladeshi labour leader, turned up dead on a roadside outside Dhaka, his body bearing the marks of torture. He had previously been abducted and tortured by domestic intelligence officials, who told him his advocacy for workers' rights and wages was hurting his country.
Within the rubble of Rana Plaza, labour activists have found labels linking European retailers and American brands to the factory. Those brands have denied having manufacturing agreements with the garment producers at Rana or have not responded to inquiries from Fairfax. One British retailer of mostly cheap fashions, Primark, reportedly confirmed it was supplied by one of the businesses operating the factory, New Wave.
Determining the ultimate destination of the clothes made at these factories is often difficult. Supply agreements are opaque, often even workers don't know for whom they are making clothes, because labels are stitched on later, elsewhere.
Tessel Pauli from the Clean Clothes Campaign said efforts at self-regulation by the companies involved in garment manufacturing in Bangladesh had failed utterly.
“It's unbelievable that brands still refuse to sign a binding agreement with unions and labour groups to stop these unsafe working conditions from existing. Tragedy after tragedy shows that corporate-controlled monitoring is completely inadequate.”
She said the families of those killed had been left even more vulnerable by this collapse.
“They, and the hundreds injured in the collapse, are without income and without support. Immediate relief and long-term compensation must be provided by the brands who were sourcing from these factories, and responsibility taken for their lack of action to prevent this happening.”
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