In the past hour, there have been hundreds of thousands of reports from users who have found themselves unable to access Twitter. As per the website downdetector.com, the social networking platform has been having issues since 2:46 p.m. EDT, presumably when the first report was made on this website.
Twitter's status page confirms the issue, noting that an investigation is ongoing regarding the "service disruption". At the time of writing, this is what the most recent update on the page reads:
[Investigating] We are currently investigating issues people are having accessing Twitter. We will keep you updated on whats happening.
The problem does not seem to only be limited to the website, but the Twitter app on iOS and Android as well. Stay tuned for updates, we'll notify you as soon as there's something to know.
Update: Well, that state of confusion certainly didn't last long; looks like it's back up for most people. Twitter has issued the following update regarding its status:
[Identified] The outage was due to an internal configuration change, which we're now fixing. Some people may be able to access Twitter again and we're working to make sure Twitter is available to everyone as quickly as possible.