It is a company that helped lift hundreds of thousands of American workers into the middle class. It transformed Detroit into the Silicon Valley of its day, a symbol of America’s talent for innovation. It built celebrated cars, like Cadillacs, that became synonymous with luxury.

And now it is filing for bankruptcy, something that would have been unfathomable even a few years ago, much less decades ago, when it was a dominant force in the American economy.

Rarely has a company fallen so far and so fast as General Motors. And while its bankruptcy appeared increasingly likely in recent weeks, the arrival of the moment is still a staggering blow, particularly for anyone with ties to the company.