Six construction workers were killed yesterday in Hong Kong's worst industrial accident in a decade, when a work platform plunged 20 floors down a lift shaft at the International Commerce Centre (ICC) - the city's tallest building. The accident happened at about 1.20pm when the six men, aged between 34 and 47, were collecting construction waste on the 30th floor of the 118-storey harbourfront landmark in Austin Road, Tsim Sha Tsui. The platform carrying the men, which is suspected to have been overloaded with construction waste, suddenly fell to the 10th floor, leaving the workers buried in debris. About 80 firefighters and paramedics were sent to the scene but rescue efforts were hampered by the narrow opening to the lift shaft and the mountain of waste inside. Three workers were found shortly after 2pm, and taken to Queen Elizabeth Hospital, where they were declared dead. Two other men were found four hours later and the last one just before 8pm. The three were certified dead at the scene. Tsim Sha Tsui Fire Station commander Lo Kam-wing said rescue work was difficult because of the limited space inside the lift shaft. 'The area of the shaft is only about two metres by three metres. A mountain of construction waste six metres deep in the shaft means we cannot let too many fire officers get in to rescue the workers,' Lo said as the rescue effort stretched into the afternoon. 'Also there is only one small exit in the lift shaft on the 10th floor. Waste and workers being carried out and fire officers going in have to share the small exit. The conditions are also very unstable; there is a danger more waste might fall from upper floors.' Distraught relatives of some of the victims gathered outside the ICC as the rescue work continued, with the brother of one worker trying to push his way into the accident site. 'Why are the safety measures so poor? Why is it taking so long to rescue them?' he yelled angrily. The families of other workers rushed to the hospital to learn the fate of their loved ones. Some of the wives collapsed and needed wheelchairs. Most of the men killed were the sole breadwinners of the families. The wife of one of the workers, named Choi, said her husband died on his first working day at the construction site. The couple had two children. The son of another victim, named Hui, said his father had also not worked at the site before. 'My father was actually off today [Sunday], but he got a phone call saying the job was rush work and so he went to work at a strange site he knew nothing about. He stepped on the platform and it fell. I want an explanation.' Choi Chun-wah, chairman of the Construction Industry Employees' General Union, said he believed the accident was caused by an unstable platform overloaded with construction waste. 'Why were so many workers on the platform at the same time?' he asked. 'Was the platform safely attached? Was there enough supervision on Sunday? The workers may have put too much waste on the platform and that led to the plunge.' Chief Executive Donald Tsang Yam-kuen inspected the site and offered his deepest condolences to the workers' families. He ordered a thorough investigation. 'One accident is too many. We must prevent a similar accident from occurring,' Tsang said. The six workers were employed by Sanfield (Management), a subsidiary of ICC's developer Sun Hung Kai Properties, Choi said. 'I don't know how much these workers were paid. But usually workers clearing waste are paid HK$500 to HK$600 for an eight-hour day.' Thomas Kwok Ping-kwong, vice-chairman and managing director of Sun Hung Kai Properties, ordered the suspension of all work at the site. 'I feel deeply grieved and heartbroken. We will help the government investigate the cause of the accident and issue a cash cheque of HK$1 million to each of the affected families,' Kwok said. The developer also promised to cover funeral expenses and provide for the education of the workers' children. A Sun Hung Kai spokeswoman said the work being carried out yesterday was legal and a safety officer was at the site. Secretary for Labour and Welfare Matthew Cheung Kin-chung, who described the incident as 'extremely serious', said the workers' families could be compensated with another HK$1.78 million under the Employees Compensation Ordinance. He said the Labour Department would launch an investigation. Eight fatal industrial accidents have been reported in the construction sector so far this year, six of them involving workers on small projects, Cheung said. Sixteen were reported last year. The ICC, designed by Kohn Pedersen Fox Associates, is the tallest building in Hong Kong. Although construction is not due to be finished until next year, offices on the lower floors have already been leased. Tenants include ABN AMRO, China Haidian, Credit Suisse, Deutsche Bank and Morgan Stanley.