UPDATE 3-Few answers and 28 still missing three days after Brazil dams burst
(Recasts, adds details on possible victims, updates mayor's condition)
By Stephen Eisenhammer
MARIANA, Brazil Nov 8 (Reuters) - Three days after a massive mudflow and flood caused by ruptured dams at an iron ore mine, Brazilian authorities are still struggling to determine a cause or even recover the bodies of as many as 28 people possibly swept away in the torrent.
The disaster in the mineral-rich southeastern state of Minas Gerais, directly north of Rio de Janeiro, has prompted a rescue and salvage operation involving about 500 people, many of whom are still searching with the help of dogs and special equipment for victims along the floodplain downstream from the dams.
Authorities late Sunday recovered two more corpses of possible victims that if confirmed would raise the death toll so far to four. Of the 28 people listed as missing late Sunday, 13 were mine workers.
The intensity of the destruction, with flooding and mud as far as 100 km (60 miles) away from the mine, has meant a slow and laborious rescue effort. It has also sparked calls by government officials, environmentalists and outraged residents for Brazil to rethink regulation of the mining industry, one of the country's biggest and a leading source of export revenue.
"We have to learn the lessons of this accident," said Fernando Pimentel, the state governor, in comments to reporters after a flyover of the devastation on Sunday. "Obviously, this wasn't enough," he added, referring to the existing regulatory framework.
Meanwhile, government leaders and residents criticized what they say has been lax communication by mine operator Samarco, a joint venture between the world's largest mining company, BHP Billiton Ltd , and the biggest iron ore miner, Vale SA .
On Sunday, BHP said Andrew Mackenzie, chief executive officer of the Australian company, was flying to Brazil to meet with Samarco executives and local authorities to better assess their needs. In a statement, the company said it was providing Samarco "with all the assistance necessary." Continuación...