At least 80 people died Wednesday when an eight-story building housing garment factories collapsed. Mohammed Neazuddin, secretary of the health ministry, confirmed the death toll, and local police said hundreds more people remained trapped under the rubble. The Rana Plaza building in Savar, a commercial hub 20 kilometers north of Dhaka, collapsed at 9 a.m., after work had started in the building's garment manufacturing units. An official at the nearby Anam Medical College Hospital, where most of the dead and injured were taken, said the dead mostly appeared to be female garment workers, although their identities could not be confirmed. Army units and fire service personnel are conducting rescue operations with help from local volunteers. A fire-service official said some 1,000 people had been rescued from under the rubble. Mehedi Hasan, who worked at the New Wave Button factory on the third floor, said that though a crack had appeared in a wall Tuesday, on Wednesday morning factory supervisors asked workers to return, claiming the building was safe. "There was a loud sound and then everything went dark," he said. "I crawled out but a lot of people are trapped inside." Attempts to reach officials of New Wave Button weren't successful. Rana Plaza leased space to four garment factories employing an estimated 5,000 workers, as well as to a bank and some shops. The bank had pulled out its employees Tuesday, locals said. A series of industrial accidents in Bangladesh has put pressure on Western clothes brands to reduce their exposure to the country. In November, more than 100 workers died in a fire at the Tazreen Fashions Ltd. factory near Dhaka, which made clothes for a number of Western brands—in some cases without the company's authorization. Following that, Wal-Mart Stores Inc., WMT +0.39% one of the companies whose garments were being made there without authorization, announced it was tightening its monitoring of third-party clothes suppliers. In 2005, the collapse of the Spectrum sweater factory in Dhaka collapsed killed 64 people and injured 80. It was unclear whether any foreign brands had contracted work to factories in Rana Plaza. Foreign garment firms conduct safety audits of factories they use, and normally avoid those based in mixed-use commercial buildings like Rana Plaza because having multiple tenants increases the possibility of hazards like blocked fire exits. But contracts to make clothes for foreign brands sometimes are subcontracted to factories in such buildings. Labor and human-rights groups have been calling on apparel brands and retailers to sign on to the Bangladesh Fire and Building Safety Agreement, which would establish a system of independent factory inspections whose recommendations would be binding. But it has yet to get off the ground. PVH, owner of Calvin Klein and Tommy Hilfiger, and German retailer Tchibo, have signed up. Other foreign companies, including Gap Inc., GPS +0.63% have their own programs. Gap has set aside $20 million to help Bangladesh factories improve safety. More than 700 worker in Bangladesh have died in fires over the past decade, according to labor groups.