From approximately 21:05 to 21:15 UTC on 2017-01-29, the forum and homepage were inaccessible due to a failed SMF database upgrade. To recover, it was necessary to restore a backup taken at 21:00 UTC. Up to 5 minutes of posts may have been lost.
This was entirely on me -- I should have tested the change more carefully, but assumed that an upgrade within the 2.0 series would be safe enough. I will be more careful in the future.