Earlier on Saturday, officials announced that the death toll from the collapse has risen to 115 dead and 248 missing.
Authorities say that 110 bodies have been recovered and 238 are listed as missing.
Helicopters hover over an iron ore mining complex to release thousands of flower petals paying homage to the dozens of victims killed and scores of missing after a mining dam collapsed there a week ago, in Brumadinho, Brazil, Friday, Feb. 1, 2019.
A video aired on local media, has captured the moment a dam at an iron ore mine in south Brazil burst, releasing a wall of toxic sludge and mud.. "Vale described the study as a routine disaster preparation plan required by regulators".
It was the second dam disaster in three years at a mine owned by Brazilian mining giant Vale.
This is the process whereby a solid material loses strength and behaves more like a liquid, and was the same issue which led to the 2015 collapse of the company's Samarco damn.
"(The study) found that the mine restaurant, where many Vale workers were likely to have died, would be hit by toxic mud. Meanwhile, the police have arrested five people in connection with the Brazil dam collapse case, the report added.
The study envisaged that sirens would alert workers if the dam burst.
Aihara said rescue teams were focusing on an area believed to have been occupied by a locker room used by employees of mining company Vale SA.
"This tragedy will be remembered not just here but all over Brazil", said 23-year-old Jonatan Silva Santos, who lost friends that worked at Vale.
Authorities have frozen over $3 billion in company assets in anticipation that it will pay damages, compensation and fines.