The Brazilian police on Tuesday arrested five people, including three employees of the giant mining company Vale, as part of an investigation into a dam rupture that left at least 84 dead and 276 missing.

The dam, filled with mining waste and sludge, burst on Friday afternoon, sending a tidal wave of mud crashing down on homes in the town of Brumadinho in southeastern Brazil. The torrent also struck Vale administrative buildings, including the company cafeteria.

The other two people arrested were engineers working for the Brazilian subsidiary of the German industrial testing company TÜV Süd, which conducted two inspections of the Brumadinho dam last year, the most recent in September, according to both Vale and TÜV Süd. The subsidiary carried out an inspection of the dam’s safety in September, it said, though it refused to comment further, citing the continuing investigation.