John Kay writes at the FT on the rise and decline of General Motors. His article is a useful one, worth reading.
For a long time GM epitomised the successful corporation, but then strengths became weaknesses and the company ossified. GM did not move with the times.
No doubt the demise of GM will be studied for years to come. I have the thought that part of the cause will be found in the failure of governance structures to move with the times, such that they bacame part of the problem as they embodied a culture locked in the past. This is supposition, but one that I suspect will be borne out in the future.