Mine Safety - Two dams burst at Brazilian iron mine

[Astronuc]

It is commons practice to dump mine tailings in an area near a mine. In areas where it rains, water may accumulate behind burms and the tailings which form an earthen dam.

In valleys, lakes can form behind dams leading to potential failures.

http://abcnews.go.com/International...village-dam-burst-mudslides/story?id=35024425

Scores missing as deadly mudslide flattens Brazil village
http://news.yahoo.com/least-17-dead-dam-bursts-brazil-mining-waste-022224741.html

http://news.yahoo.com/photos/two-da...-at-brazil-iron-mine-photo-1446841117332.html

In Brazil, two dams failed flooding several villages down the valley.

Dozens missing in Brazil mine disaster, death toll uncertain
http://news.yahoo.com/dam-burst-vale-bhp-mine-devastates-brazilian-town-013112268--finance.html

Walls of water filled with mining waste cascaded downhill when the dams burst on Thursday, engulfing a nearby village in a sea of mud and flooding others far removed from the open-pit Samarco mine jointly owned by BHP Billiton and Vale.

The water and mud was reported to be 15 to 20 in depth, or height.

About 80% of the village Bento Rodrigues (which is about 93 miles (150 km) southeast of Belo Horizonte, Brazil's third largest city and the capital of the mining state of Minas Gerais) was destroyed. And authorities have trouble reaching the area.

 

[Borg]

Google Earth gives a good view of what was sitting above them before the collapse.

And this is just the very bottom of a much larger mining area.