sludge

Residents at the time described seeing slurry carrying "trees and big boulders", and buildings left deep in sludge and mud.

Splotches of mysterious sludge stick to the stone floor.

The sludge swept through communities, destroying hundreds of people's homes and poisoning the river.

According to the victims' lawyers, BHP was aware that toxic sludge was accumulating at at the facility in Minas Gerais state north of Rio de Janeiro at rates that far exceeded the annual limit.

The tsunami coming ashore mixed with soil, sewage, oil, and rubble to form a fast-moving black sludge.