Dhaka: A top investigator probing last week's garment factory disaster in Bangladesh on Friday blamed vibrations from four illegal generators for the collapse of the building which killed more than 500 workers. (Agencies)
The preliminary findings of the government probe, as described by lead investigator Main Uddin Khandaker, gave the clearest explanation yet for the tragedy.
"Four huge generators were set up on each of the top floors where garment factories were located, violating rules," Khandaker, a senior home ministry official said.
"When these generators were started after a power cut they created vibration, and together with the vibration of thousands of sewing machines, they triggered the collapse," he said, adding a final probe report would be submitted after the conclusion of the recovery operation.
Khandaker said that the building, Rana Plaza, was built "for commercial use" and not to be a factory; it could not withstand the vibrations because the owner used sub-standard rods, bricks and other material to construct it.
It also emerged today that an engineer who had warned that the building may be unsafe before it imploded on April 24 was being questioned by police after becoming the latest person to be arrested over the disaster.
Civil engineer Abdur Razzaq Khan was detained last night after police said he had given the building the all-clear on April 23 after inspecting the cracks.
Dhaka deputy police chief ABM Masud Hossain said investigators found that Khan had cleared the building to continue operating while also suggesting the owner seek further advice.
Captain Shakiur Rahman, an officer in a special army control room set up to coordinate the rescue operation said, "Death toll now stands at 525".
Dozens more people are thought to have been buried alive after the eight-storey building collapsed in Savar, which lies around 30 kilometres (20 miles) to the northwest of the capital Dhaka.
Some Western fashion brands have said they are considering their future in Bangladesh and Disney has already announced it is pulling out of the country.
Prime Minister Sheikh Hasina has maintained that "Bangladesh now is a place for good conditions for investment" but also suggested Western firms drawn to the country by cheap labour costs could hike salaries to improve the way businesses are run.
Dhaka: A top investigator probing last week's garment factory disaster in Bangladesh on Friday blamed vibrations from four illegal generators for the collapse of the building which killed more than 500 workers.