Twitter.com became inaccessible from two browsers, Google Chrome and Firefox, for HuffPost staffers starting around 4 p.m. ET. However, Twitter's iOS apps for iPhones and iPads seem to be working fine -- if you really need to scratch that Twitter itch.
The website downrightnow also reported the outage, writing that it is having "Likely Service Disruption." A similar site, "Down For Everyone Or Just Me," also noted that "It's not just you! http://twitter.com looks down from here."
We've reached out to Twitter and will update with comment when we receive it.