The team got notifications that West US was having problems Friday evening. After investigation, it was found that the West US region's endpoint was failing DNS resolution. After several troubleshooting steps and reaching out to the Windows Azure Live Site team to inquire about known DNS issues, the issue resolved itself.
This was the first time we encountered an issue of this type, and an investigation continues to be underway to identify the root cause.
The outage in UTC was Saturday Feb 17 at 2:50 AM to 7:43 AM.