It's back up now.<p>Commercial aviation is generally well known for having redundancies in place for a lot of problems they can potentially face, so I have to wonder how big the issue was that they had to shut down an entire airspace. Could have been a one-in-a-million glitch they couldn't account for. The subsequent investigation report will be an interesting read.
This brings to mind a crazy story about Skyguide that I heard. Skyguide was implicated in a midair collision between two aircraft in 2002. A family member of one of the deceased later murdered a Skyguide employee in an act of vengeance.<p><a href="https://en.wikipedia.org/wiki/2002_%C3%9Cberlingen_mid-air_collision" rel="nofollow">https://en.wikipedia.org/wiki/2002_%C3%9Cberlingen_mid-air_c...</a>