Officials suggested the wall coming loose could have been caused by heavy rains caused by recent flooding in the state, pand forced almost 17,000 people out of their homes.
At least seven people have died and nine were seriously injured after a wall of rock collapsed on top of motor boats below a waterfall in southeastern Brazil.
A tower of rocks suddenly broke away from the canyon wall and came crashing down on several leisure boats on Saturday, sending out a huge wave over the lake at Capitolio, in Minas Gerais state.
Videos posted on social media showed tourists shouting as the column of rock crashed into the water, smashing two boats.
Authorities said three people were still missing after others feared lost were located by telephone. Divers searched the lake.
The people hurt in the accident had broken bones and one was in serious condition in hospital with head and facial injuries. Some 23 others were treated for light injuries, he said.
The region has been under heavy rainfall for two weeks, which could have loosened the rock face. On Saturday, a dike overflowed at an iron ore mine 300 kilometers to the east, cutting off a major federal highway.
Minas Gerais Gov. Romeu Zema sent messages of solidarity with the victims via social media.
At least five people died and nine were seriously injured when a wall of rock collapsed on top of motor boats below a waterfall in southeastern Brazil pic.twitter.com/7iXktSyAT8— TRT World (@trtworld) January 8, 2022
Authorities to investigate accident
Furnas Lake, which was created in 1958 for the installation of a hydroelectric plant, is a popular tourist draw in the area roughly 420 kilometers (260 miles) north of Sao Paulo.
Officials in Capitolio, which has about 8,400 residents, say the town can see around 5,000 visitors on a weekend, and up to 30,000 on holidays.
Earlier last year, the concern was a lack of rain as Brazil experienced the worst drought in 91 years, which forced officials to alert the water flow from the Furnas Lake dam.
The Brazilian navy, which also helped in the rescue, said it would investigate the causes of the accident.
Even in the dry season, in some parts of the lake the movement is so intense that the boats have to take turns to navigate on the lake, said the City Hall press office.