The video is terrifying ... literally, a side of a mountain cascaded down onto 4 boats in Minas Gerais. You hear boaters scream in disbelief, as the rock formation makes contact with the boats, hurling them into the air. Two of the 4 boats hit sank.
The collapse was thunderous ... as thousands of pounds of rock and debris hit the water. It's all the more horrifying that it was by all accounts a serene day and you see the boaters relaxing and enjoying themselves until disaster suddenly struck.