The tweets went silent for a time on Thursday.
Social media service Twitter was not working for about an hour on Thursday afternoon. The company says some people may now be able to access the site again.
Twitter said in a statement Thursday afternoon that it was 'currently investigating issues people are having accessing Twitter.'
Users can continue to monitor the site's status at status.twitterstat.us. It's unclear at this time how extensive the outage was or its exact length.
'The outage was due to an internal configuration change, which we're now fixing,' Twitter said in an update it posted to the status monitoring site.
The site's outage coincided with the start of the White House's Presidential Social Media Summit. Twitter, along with Facebook, wasn't invited to the summit, while a number of right-wing extremists were.