According to various media sources, including Twitter, Wikipedia has now been down for more than an hour and no real explanation had been given.
The current message given on the Wikipedia site to those not back on line was:
Sorry! This site is experiencing technical difficulties.
Try waiting a few minutes and reloading.
Reloading doesn't work though as it seems that Wikipedia is experiencing more than just a minor blip in service.
reports that Wikipedia last experienced major downtime back in March when a European datacentre overheated and meant that Wikipedia was forced to use back-ups in Florida. That process caused major DNS problems which left much of the service inaccessible.
Wikipedia now says that a power outage at the Florida data centre is to blame and confirms with this message, “Thanks for being patient, everyone. We’ve figured out the problem: power outage in our Florida data center. Slowly coming back online!”