Brazilian officials on Sunday resumed the search for hundreds of missing people in the wake of a massive dam collapse, with firefighter crews returning to mud-covered areas after a several-hour suspension over fears that a second dam was at risk of breach.
Authorities evacuated several neighborhoods in the southeastern city of Brumadinho that were within range of the B6 dam owned by the Brazilian mining company Vale.
An estimated 24,000 people were told to get to higher ground, but by the afternoon, civil engineers said the second dam was no longer at risk.
Areas of water-soaked mud appeared to be drying out, which could help firefighters get to areas previously unreachable.
"Get out searching!" a woman yelled at firefighters near a refuge set up in the center of Brumadinho. "They could be out there in the bush."
On Sunday, authorities lowered the confirmed death toll to 37 from 40, giving no explanation, though that number was expected to increase as rescue and recovery teams got to the hardest hit areas.
Even before the latest news, hope that loved ones had survived a tsunami of iron ore mine waste from the first dam was turning to anguish and anger over the increasing likelihood that hundreds of people had died.
Caroline Steifeld, who was evacuated, said she heard warning sirens on Sunday, but no such alert came on Friday, when the first dam collapsed.
"I only heard shouting, people saying to get out. I had to run with my family to get to higher ground, but there was no siren," she said, adding that a cousin was still unaccounted for.
For some anguish has turned to anger as they await news of their loved ones.
"I'm angry. There is no way I can stay calm," said Sonia Fatima da Silva, as she tried to get information about her son, who had worked at Vale for 20 years.
"My hope is that they be honest. I want news, even if it's bad."
Da Silva said she last spoke to her son before he went to work on Friday, when around midday a dam holding back mine waste collapsed, sending waves of mud for kilometers (miles) and burying much in its path.
Romeu Zema, the governor of Minas Gerais state, said by now most recovery efforts will entail pulling out bodies.
President Jair Bolsonaro, who headed to the scene on Saturday, described the collapse as a “tragedy”.
Local television channel TV Record showed a firefighters’ helicopter hovering inches off the ground as it pulled two people covered in mud out of the sludge in the first few hours after the collapse.
Seven bodies had been recovered by late on Friday, according to the governor’s office of Minas Gerais state. But it was feared the death toll would grow as rescue and recovery teams dug through feet of mud.
Fabio Schvartsman, CEO of mining company Vale, said he did not know what caused the collapse.
About 300 employees were working when it happened.
Aerial footage shows the extent of flooding caused by the collapsed dam
About 100 had been accounted for, and rescue efforts were under way to determine what had happened to the others.
"The principal victims were our own workers," Mr Schvartsman told a news conference, adding that the restaurant where many ate "was buried by the mud at lunchtime".
After the dam collapsed in the afternoon, parts of Brumadinho were evacuated, and firefighters rescued people by helicopter and ground vehicles.
Photos showed rooftops poking above an extensive field of the mud, which also cut off roads.
The flow of waste reached the nearby community of Vila Ferteco and a Vale administrative office, where employees were present.
“I’ve never seen anything like it,” said Josiele Rosa Silva Tomas, president of Brumadinho residents association. “It was horrible… the amount of mud that took over.”
Ms Silva Tomas said she was awaiting news of her cousin, and many she knew were trying to get news of loved ones.
Another dam administered by Vale and Australian mining company BHP Billiton collapsed in 2015 in the city of Mariana in Minas Gerais state, resulting in 19 deaths and forcing hundreds from their homes.
Considered the worst environmental disaster in Brazilian history, it left 250,000 people without drinking water and killed thousands of fish.
An estimated 60 million cubic meters of waste flooded rivers and eventually flowed into the Atlantic Ocean.
Mr Schvartsman said what happened on Friday was “a human tragedy much larger than the tragedy of Mariana, but probably the environmental damage will be less”.
The state fire department said about 300 people were missing. The Minas Gerais governor’s office said 150 were missing.
Mr Bolsonaro, who assumed office on January 1, said he lamented the accident and sent three cabinet ministers to the area.
“We will take all the possible steps to minimise the suffering of families and victims,” Mr Bolsonaro said.
More than 100 firefighters were on the scene and another 200 were expected to arrive on Saturday.