Severe storms caused an outage of Amazon's Web Services in northern Virginia.

Storm took down Netflix, Pinterest, Instagram and other sites due to an outage in northern Virginia.
According to Amazon Web Services, at 8:21 p.m. PDT it was "investigating connectivity issues for a number of instances" in the East region. By early Saturday morning, Amazon said it was "continuing to work to recover."
Netflix, Pinterest were back up, but as of early Saturday Instagram was still down.

(Source)