Systems and products that we design operate often in the “normal mode of operation”, and this makes us somehow think that they are always safe in their modes of operation because no accident was seen or reported. However, the foreseeable modes of operation have to be safe. For example, the power transmission system has to be safe in its normal mode of operation, or when it rains, storms or floods. Here is an example of safety failure when the system fails unsafely under exceptional mode of operation.
So sad to see this failure.