Okay kiddo, I will explain what happened with the Bento Rodrigues dam disaster like you're five years old.
A long time ago, in a place called Brazil, there was a big wall that people built to hold a lot of water. This wall was called a "dam" and it was built to make electricity and to help people have water to use.
One day, something went really wrong with the dam. The wall started to break and the water in the dam started to come out really fast. The water was so powerful that it destroyed everything in its path, like a big wave.
Many houses, buildings, and trees were destroyed, and some people got hurt or even died because of the flood. They had to leave their homes because they were all wet and broken.
After the disaster, people worked really hard to fix the dam and help the people who got hurt. They also made new rules to make sure that something like this doesn't happen again.
So, that's what happened with the Bento Rodrigues dam disaster, and now people are more careful when they build dams to make sure they are safe and won't hurt anyone.