Jan 27, 2012, 16:04 GMT
Rio de Janeiro - The death toll climbed to nine from the collapse of three buildings in central Rio de Janeiro, officials confirmed Friday, but the cause of the accident remained unclear.
At least 15 people were still missing from Wednesday's collapse of three adjacent office buildings - 20, 10 and four storeys high - in the heart of the city. At the time, most of the occupants had left work.
The deputy chief of the Fire Department, Ronaldo Alcantara, said more bodies would most likely be retrieved within a few hours.
'We think we have reached the room where a training session for computer technicians was taking place, which is where the greatest number of people was concentrated at the time of the accident,' said Alcantara.
Rescue efforts continued uninterrupted overnight despite the rain, but the chances of finding survivors were regarded as slim. About 100 Fire Department workers continued to look for the missing Friday.
Rio de Janeiro Mayor Eduardo Paes said 15,000 tons of rubble - 80 per cent of the total - had been removed from the site by early Friday.
There were still no 'definitive answers' to the cause of the accident, he said.
Investigators were reportedly focusing on possible structural defects in one of the buildings, most likely the tallest, because of illegal work by the occupants to alter at least two floors.
'We are collecting information from the experts who were at the site, and everything will be verified. Nobody can say yet whether it was caused by structural damage. There are several hypotheses that will be assessed and analyzed,' said Paes.
Sydnei Menezes, the head of Rio's Council of Architecture and Urban Planning, said there had been no sign of structural problems in the buildings. 'There was a sudden collapse of the structure. It was an unprecedented event.'
The accident has renewed concerns about safety in Rio de Janeiro, which is to host the Football World Cup in 2014 and the Olympic Games in 2016.
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