Troops have already set up at least one bridge in the mountain vacation city of Teresopolis, officials said, but at least 10 main highways remain blocked in the rugged area north of Rio where the slides hit, hampering efforts to move in the heavy machinery needed to begin massive clean up efforts and eventually dig out bodies stuck under tons of mud and debris.
The troops plan to set up mobile bridges that can span 200 feet and are robust enough to support the hundreds of pieces of big equipment needed in clean up and recovery efforts.
Days of heavy rains unleashed tons of earth, rock and raging torrents of water down steep, forested mountainsides Wednesday, directly into towns that are weekend getaways for the Rio area.
Rescuers had yet to reach about 20 neighborhoods, though a break in rains and better visibility allowed about 12 helicopters to begin taking supplies and firefighters in, while shuttling injured survivors out.
But pilots said flying was still treacherous in the area full of jagged mountain peaks, where there are few safe landing zones and power lines are draped between peaks through seemingly clear space.
"These are the most challenging conditions I've flown in," said Adalberto Ortale, a helicopter pilot for Ibama, the enforcement branch of the Environment Ministry. "The majority of people doing the flying are not from here and you have to orient yourself on the fly."
All levels of government have come under heavy criticism for not alerting people to the dangers - and of allowing homes to be built in high-risk areas. Local mayors have said they did not receive any warning a storm of that magnitude was about to hit.
Brazil's minister of science and technology, Aloizio Mercadante, said 5 million Brazilians live in some 800 areas at high risk for mudslides and floods across the nation, but that it would take at least four years for a nationwide alert system to be in place, the Folha de S. Paulo newspaper reported on its website Monday.
Mercadante offered few details on how such a system would be built.
After a meeting with President Dilma Rousseff in Brasilia, Mercadante said Brazil has a relatively robust system of collecting weather information via satellite and radar, but that the nation needs more people to interpret the data and alert local officials to dangers in a coordinated manner.
In downtown Teresopolis, frustration and hopelessness was building. Hundreds of survivors remained uncertain of how they were going to be able to leave crowded shelters and restart their lives.
Eunice Peixoto de Souza, 57, said she was thankful for the shelter and the hot lunches served at the Teresopolis gymnasium where she has been staying for five days with three of her children and three grandchildren. But she has nowhere else to go, and the prospect of spending another week, or weeks, on the thin foam mattresses laid on the floor is hard to bear.
"We lost everything, and we can't pay rent," she said. "I want a place that will let the family stay together, but I haven't heard any word from the government yet."
One of her sons is still living in his home in a high-risk area. Peixoto de Souza wants him to leave, but knows he won't want to bring his children to the cramped gym.
"What can I tell him? Take them to live under a bridge?" she asked, upset. "We're waiting for some word from the government. I am certain that God will provide."
In Teresopolis, mayors from the three cities hardest hit planned to begin coordinating reconstruction efforts, which have been roughly estimated at $1.2 billion dollars.
At least 5,000 new homes must be built for those who lost everything. Roads, bridges and commercial buildings need to be repaired or razed and replaced.
Mayor Jorge Mario Sedlacek of Teresopolis said that more than 2,000 tents were being brought in, each capable of sheltering up to 10 people. Teresopolis has more than 3,000 people who were made homeless by the slides.
Rio state's Civil Defense department said on its website Monday that the death toll reached 665 between the cities of Teresopolis, Nova Friburgo, Petropolis and Sumidouro.