DHAKA, Bangladesh – Ten days after the horrifying collapse of a garment-factory building, the death toll rose to 547 on Saturday.

Since the April 24 collapse in the Dhaka suburb of Savar, high temperatures have generally been 90 degrees or above, and lows have rarely dipped below 80 degrees. Bodies have decomposed beyond recognition, said Mohibul Alam, a firefighter at the collapse scene.

But he added that some could still be identified because the victims’ identification cards were found with them.

Some of the victims who had been closest to escaping appear to be among the last to be recovered. Only now have rescuers dug deep enough, using cranes and other equipment, to approach the stairs of the ground floor. The official death toll from the collapse was expected to climb. The official number of missing has been 149 since Wednesday, although unofficial estimates are higher.

The disaster is likely the worst garment-factory accident ever, and there have been few industrial accidents of any kind with a higher death toll.

It surpassed long-ago garment-industry disasters such as New York’s Triangle Shirtwaist factory fire, which killed 146 workers in 1911, and more recent tragedies such as a 2012 fire that killed about 260 people in Pakistan and one in Bangladesh that same year that killed 112.

Bangladesh’s $20 billion garment industry supplies retailers around the world and accounts for about 80 percent of the impoverished country’s exports. The collapse has raised strong doubts about retailers’ claims that they could ensure worker safety through self-regulation.

Five garment factories operated in the Rana Plaza building that collapsed, and many brand labels have been found in the wreckage, but only two retailers, Britain’s Primark and Canada’s Loblaw Inc., have acknowledged that their clothes were being made there at the time.

Loblaw’s CEO has decried the “deafening silence” from what he said were more than two dozen other international retailers who used garment factories in the collapsed building.

Mainuddin Khandkar, the head of a government committee investigating the disaster, said Friday that substandard building materials, combined with the vibration of the heavy machines used by the five garment factories inside the Rana Plaza building, led to the horrific collapse.

Because of a power outage, heavy generators were turned on about 15 minutes before the building fell, he said.

The building developed cracks a day before the collapse, and Rana Plaza owner Mohammed Sohel Rana called engineer Abdur Razzak Khan to inspect it.

Khan appeared on television that night and said he told Rana the building should be evacuated.

Police also issued an evacuation order, but witnesses said that hours before the collapse, Rana told people that the building was safe and garment factory managers told their workers to go inside.

In New Delhi on Friday, Bangladesh Finance Minister Abul Maal Abdul Muhith downplayed the impact of the disaster on the garment industry, which is by far the country’s biggest source of export income.

“The present difficulties … well, I don’t think it is really serious – it’s an accident,” Muhith said. “And the steps that we have taken in order to make sure that it doesn’t happen, they are quite elaborate and I believe that it will be appreciated by all.”