Bangladesh factory building collapse death toll exceeds 500 Bangladesh factory building collapse - garment workers attempt to flee the eight-storey Rana Plaza complex in Savar. Photographs: Andrew Biraj/Reuters The death toll from the collapse of a Bangladesh factory building has passed 500, officials said, as police investigating the disaster arrested an engineer who warned the day before the tragedy that the eight-storey complex was unsafe. The detention of Abdur Razzak brought to nine the number of people held over the disaster, which has put the spotlight on the many western clothing retailers using the country as a source of cheap goods. Scores of relatives remained at the site in a Dhaka suburb on Friday, clutching photographs of loved ones attesting to the many more still missing, as the number of deaths in the country's worst industrial accident rose to 501. Razzak had been called to Rana Plaza in Savar, 20 miles north of the capital, by its owner when cracks appeared in concrete pillars the day before the accident. Despite his warning that the building was unsafe - quoted in local media hours before it came crashing to the ground - thousands of mostly female workers were sent back into its upper-storey factories when the morning shift began the next day. Police said Razzak had been arrested because he had been involved in the construction of the building. Duty-free access offered by western countries and low wages have helped turn Bangladesh's garment exports into a $19bn (£12bn) a year industry, with 60% of clothes transported to Europe. People mourn for relatives trapped under the rubble of the building The EU said it was considering trade action against Bangladesh, which has preferential access to EU markets for its garments, to pressure Dhaka to improve safety standards. About 3.6 million people work in Bangladesh's garment industry, making it the world's second-largest clothing exporter after China. Some earn just $38 a month, conditions Pope Francis on Wednesday likened to slave labour. There were about 3,000 people inside the complex, which was built on swampy land, when it collapsed. About 2,500 people have been rescued, many injured, but many remain unaccounted for. The building's owner, Mohammed Sohel Rana, his father, four factory owners and two engineers have been arrested, while the local mayor has been suspended from office accused of improperly approving its construction. It was the third deadly incident in six months to raise questions about worker safety and labour conditions in Bangladesh. In November, scores died in a garment-factory fire in Dhaka, many of them because supervisors ordered workers back to their stations even as an alarm rang and smoke rose through an internal staircase. Human-rights groups say there has never been a case in which a factory owner was prosecuted over the deaths of workers.