By: H. Esteves
One hundred and eighty. That is the number of identified deaths in Brumadinho, Minas Gerais, and one hundred and thirty-one people are still to be found (as from 26/02/19). Eighty people have been left homeless in the incident.
What is worse is that the accident in Mariana should have served as a warning to Vale - the mining company in charge of the dam - since it left fifteen people dead and four people missing. However, the company committed the same mistake once more.
The mud taking over the town of Brumadinho can be seen above. BBC estimates that mud travelled about 80 km per hour initially and slowed to 20 km per hour. For comparison, the average human sprints at about 25 km per hour in 100 meters. So it would be virtually impossible to outrun the mud. Therefore, most survivors lived due to either being above the mud or escaping in a vehicle. Video evidence shows tragic scenes, such as a man escaping in a truck rapidly becoming surrounded by mud. In short, it was exceedingly hard to run away which resulted in the high number of casualties.
But what is the reason behind the tragedy?
The problem with the mud dam is that whoever was responsible for building it did so higher than what was ideal. However, such higher structure wasn't done properly. Consequently, there wasn't enough support to the new height and too much pressure on the original structure. The problem increases with how many new heights you add to the original without the correct base.
The picture above clearly demonstrates the three methods for a mud dam. The upstream construction method is good on one hand because it is the cheapest and easiest to build. On the other hand, it isn’t safe. And the Brumadinho and Mariana dams were built following the upstream method rather than the safer downstream method, which provides a lot of support to the structure… Or even the centerline method, which provides some base to the structure.
These are the full details of the Brumadinho crisis. Many are on trial and a few have already imprisoned. Vale has also had to pay many fines and their president (along with a few directors of the company) were temporarily removed control of the company.