What caused the internet outage that brought down Amazon, Reddit and Gov.uk?

Problem at content delivery network provider Fastly is part of growing need for speed online

• Massive internet outage hits websites including the Guardian

For 45 minutes in the UK morning, a significant chunk of the web did not work. People trying to visit a huge array of websites, from the Guardian through Gov.uk to Reddit, Hulu and the White House, received a blank white page and an error message telling them the connection was unavailable.