Here's why Healthcare.gov broke down

For the past two weeks, healthcare.gov, the federal government's new health insurance marketplace, has been bogged down by problems, preventing users (including me) from viewing insurance options and plans on the website. Federal officials have pointed to overwhelming demand to explain the site's problems. But web developers, other experts and journalists have uncovered more fundamental issues with the design and functioning of the site. Here are excerpts from five of the better stories explaining what happened.