No law firm collapse has left a more indelible mark on the legal profession than the spectacular failure of Dewey & LeBoeuf. While many remember the outsize guarantees and the drawing down of credit lines that helped bring about its demise, the firm was also pinned with another immense financial burden: a generous, underfunded pension plan.

For some firms in the Great Recession, reduced revenues combined with the overwhelming pressure from multimillion-dollar pension liabilities—a holdover from the days when pensions were simply a promise firms made to retiring partners—were too much to bear.