Spare a thought for San Francisco commuters who face their second day of rush-hour delays following the closure of the San Francisco-Oakland Bay Bridge after a major repair failed Tuesday night bringing down several pieces of steel on to passing vehicles. The incident raises questions about the strength of the bridge in the event of an earthquake. The state of the nationÃ¢â‚¬â„¢s crumbling infrastructure has been a growing concern ever since the levee failures in New Orleans after Hurricane Katrina in 2005 and the Minneapolis Interstate 35W bridge collapse in 2007. Last year a report by the American Association of State Highway and Transportation Officials (AASHTO) warned that within the next 15 years almost half of AmericaÃ¢â‚¬â„¢s bridges will be over 50 years of age, exceeding the life span for which they were designed. One in four of the bridges are rated as deficient, either in need of repair or in need of widening to handle todayÃ¢â‚¬â„¢s traffic. In its 2009 Report Card for AmericaÃ¢â‚¬â„¢s Infrastructure the American Society of Civil Engineers (ASCE) assigned a grade of D to the nationÃ¢â‚¬â„¢s infrastructure and warned that $2.2 trillion in repairs and upgrades is needed over the next five years to meet adequate conditions. ItÃ¢â‚¬â„¢s worth noting that insurance dollars play a vital role in helping rebuild private and public infrastructure in the wake of disaster. Check out the I.I.I. online publication A Firm Foundation for more on how insurers support the U.S. economy.