A large piece of rock is to blame for last month’s fire at Vale.

The joint investigation is complete, and it concludes that the rock hit a scoop tram that was being operated remotely inside a production block. This caused an electrical fire and the malfunction of the on-board fire suppression system, trapping 39 miners at T1 mine.

Thanks to safety procedures in place, no one was hurt and all workers were eventually brought to the surface.

Damage and replacement costs are estimated at $1 million.