What's behind America's baby formula crisis?

Empty store shelves, higher prices and retailers limiting sales have caused parents across the U.S. to scramble to find baby formula. Abbott, the nation's biggest infant formula maker, recalled several products and temporarily shut down its Michigan manufacturing plant in February after bacteria was found at the site. But it wasn't just the plant shutdown that caused the supply problems. CNBC explores what led to the crisis in the first place and how the U.S. can prevent it from happening again.