It turned out that my hosting and domain registration accounts had expired. I never received a bill to renew either of these as I did last year, so I was unaware of the pending expiration. I’ve taken this opportunity to switch providers to uplinkearth. My previous host, Sharp Web Services, took ~48 hours to respond to their “emergency” email and never did answer their phone. Completely unacceptable! I would never recommend doing business with them. Uplinkearth responded to my one request within an hour and has been very easy to work with so far.
Sorry for the downtime. I’m finally back online and functioning again.