A nationwide crime wave is forcing many retailers, large and small, to close their doors or lock up their merchandise.One example is Nordstrom, which made an announcement in May that it's closing its flagship store in downtown San Francisco after 35 years in business.The location inside Westfield Mall said goodbye to its last customers on Aug. 27, after opening in October 1988.The store at the corner of Fifth and Market Streets once occupied five floors and spanned more than 312,000 square feet but is now closing like many other retailers because of a surge in crime and poor sales.San Francisco...