At least, I have nobody to blame but myself. I stuck with Washington Post Co. stock even after I left the company and shifted out of its 401(k) plan. Intellectually, I knew it wasn’t a great idea to hold company stock, but emotionally, I found it hard to let go, so I just reduced the percentage of Post in my portfolio.

Lots of workers who, like me, invested in their employer’s stock have watched that stock price fall in the deteriorating economy. But at some companies, particularly in the financial services industry, charges are being made that management knew about underlying dangers to the stock price and breached a duty to employees by allowing workers to continue to hold company shares without disclosing the risk.

Such claims have been filed in earlier financial scandals and in other industries—for instance, in the wake of the collapse of Enron and WorldCom. But now, with massive carnage in the financial sector and real estate, it’s likely many more will be coming.

Just last month, Merrill Lynch agreed to pay $475 million to the Ohio State Teachers Retirement System and other shareholders and to pay $75 million to settle claims filed by company employees who held the stock in retirement plans. The settlement has yet to be finally approved.

Merrill Lynch spokesman Mark Herr said in an e-mailed statement that the company was “pleased to have taken these steps towards putting these lawsuits behind us. Although we vigorously disputed the allegations in these cases, we concluded it was best to avoid the uncertainty, distraction and costs of the litigation, and to try to achieve certainty through these settlements.”

The Ohio lawsuit claimed that Merrill Lynch had created a huge exposure to risky investments related to subprime mortgages without disclosing the risk adequately and even seeking “to minimize, hide and obscure Merrill’s exposure by falsely representing that Merrill’s risk controls and hedging techniques were effectively mitigating and minimizing any impact that subprime issues would have on Merrill.” Moreover, the suit claimed, the defendants “falsely led investors to believe that the impact of subprime issues would be minimal on Merrill by repeatedly representing that Merrill’s revenues from its subprime-related activities were less than 1 percent of Merrill’s net revenues.”

According to press reports, other firms hit with similar lawsuits include Lehman Brothers Holdings Inc., AIG, Wachovia Corp. and IndyMac Bank.

Such litigation may indicate that, in broad terms, a company is responsible for the management of employee benefit plans. It also underscores the danger an employee faces when holding too much company stock in a workplace savings plan. “The punch line is that a lot of people have all or a large portion of their 401k money in one stock,” says Damon Silvers, associate general counsel for the union federation AFL-CIO.

Lawsuits are one way to try to determine who is to blame for retirement savings lost when stock prices crash—and whether anything can be recovered. “When these things go to zero, there are often no assets to be had,” he said. Workers at firms that are acquired by other companies may have more luck, he said.

Despite the dangers of investing in an employer’s stock, many workers continue to do so. In a 2008 study of firms where company stock was a retirement plan investment option, 36 percent of employees had more than 20 percent of their investments in that stock—a very high percentage for a single stock. The study, conducted last year by Financial Engines, a Palo Alto, Calif., advisory services firm, also noted that older workers usually had the highest concentration of company stock—a danger because they have less time to recover if the stock plummets.

But even without a dramatic drop in company stock, investing heavily in the company where you work hurts your bottom line. The Financial Engines report found that a retirement plan with 80 percent company stock would yield 42 percent less after 20 years than a plan with 20 percent. The report assumed the same starting balance and no future contributions.

Why do workers choose their own company’s stock over more diversity in their portfolios? The reasons include sentimentality (as in my case), a belief that they are in a good position to assess the company’s chances of success, or maybe a belief they are investing in themselves.

But the real problem lies in the way retirement savings plans are set up. It’s something companies that offer traditional pension plans would never do, or be allowed to do: put the responsibility for retirement savings plans in the hands of those untrained to do so. That’s you and me, folks, unless you happen to be an investment professional.

In recent years, efforts have been made to help workers manage their investments—for example, by offering target-date funds. Target-date funds set a date for retirement and ratchet down risk as the worker draws closer to that date. Instead of an individual choosing investments and rebalancing them as retirement draws nearer, a professional does it.

Despite improvements, retirement savings plans can still be way too risky, as the financial meltdown has made distressingly clear.

Martha M. Hamilton was a writer and editor for the Washington Post for more than 30 years. She writes a regular column, Your Financial Future,  for AARP Bulletin Today.