zalt,
They are better now for modern helicopters. That accident was a chain, like all accidents. The position of the engines on ancient helicopters makes it such that an engine burst will cut the primary flight controls, which is the real cause of that accident. Modern regulations require that any turbine will burst, and the aircraft's design must account for that by withstanding that burst.
The Super Puma family cannot be redesigned to prevent this, in fact, the 225 does not meet this new turbine burst requirement. Instead, regardless of the requirement to withstand a burst, the engines are said to not be able to burst. The regulation is not met, however.
The S92, and the other more modern helicopters, are designed so that a turbine burst does not allow engine chunks to cut primary flight controls. The A-139 has similar design features, I believe.