Parts of a cliff face fell onto boaters on Brazil's Furnas Lake© Provided by DW Parts of a cliff face fell onto boaters on Brazil’s Furnas LakeEdgard Estevo, commander of the Minas Gerais State Fire Department, said as many as 20 people were believed to be missing and officials were seeking to identify them.

Officials said at least 32 people had been injured but most had been released from hospitals by Saturday evening.

Video images showed a group of small boats drifting near a waterfall below a cliff on Furnas Lake when a piece of rock broke off, hitting at least two of the boats.

Another video on social media shows the minute before the incident, with people warning that “many stones are falling” and advising other boats to move away from the rocks.

Where did the accident occur?

Estevo said the incident occurred between the towns of Sao Jose da Barra and Capitolio, located in Brazil’s southeastern Minas Gerais state. The boats had left from the town of Capitolio.

Furnas Lake was originally formed along with the creation of a hydroelectric dam and is a major tourist attraction in the area.

Tourists come to see the rock walls, caverns and waterfalls surrounding the Furnas Lake’s waters.

Why did the accident happen?

Officials suggested that the rock could have come loose due to recent heavy rains that caused flooding in the state and displaced 17,000 people.

Pedro Aihara, spokesperson for the Minas Gerais State Fire Department, told Brazilian broadcaster GloboNews that the rocks in this area are “more susceptible to the effects of wind and rain” and “show less resistance.”

Brazil: Several dead as cliff collapses on boats (msn.com)