Retirement crisis

I’m writing an article for “U.S. News & World Report” about retirement – specifically, I’d like to hear from economists, futurists and/or retirement experts who have thoughts on what will happen in 10-30 years if people continue to have trouble saving money for retirement. In other words, you hear a lot about a “retirement crisis.” What will that look like if the country does have one? I’m looking for likely worst case scenarios and what types of solutions you think there are (or will be) to solve the retirement crisis.