We have identified the root cause to be an internet outage in AWS. The following update has been posted by AWS via https://status.aws.amazon.com/
7:43 AM PST We are investigating Internet connectivity issues to the US-WEST-2 Region.
8:01 AM PST We have identified the root cause of the Internet connectivity to the US-WEST-2 Region and have taken steps to restore connectivity. We have seen some improvement to Internet connectivity in the last few minutes but continue to work towards full recovery.