Facebook was still down for some people as of early Thursday morning, more than 12 hours after problems began popping up and users started reporting issues online.
People reported problems since a little before noon Eastern on Wednesday, according to downdetector.com. The reports slowed around 10 p.m. Eastern, but repeatedly bounced back up a number of times throughout the day.
As of late Wednesday, the majority of the issues appeared centered in New York, Los Angeles, San Francisco, Seattle and Tokyo.
Earlier in the day, users were reporting that just certain pages wouldn't load, and they had been getting a message from Facebook that the site would be back soon.
"Facebook is down for required maintenance right now, but you should be able to get back on within a few minutes," the message read.
But hours later and folks were still having problems on the social media site and its family of apps, including Instagram.
The company had been keeping quiet about Wednesday's issues, except for two tweets on its official Twitter account.
Facebook said around 2 p.m. Eastern that it was "working to resolve the issue," then followed-up an hour later to confirm the issue "is not related to a DDoS attack," which is a distributed denial of service attack.
San Francisco news anchor Raj Mathai tweeted Wednesday night, citing an internal Facebook source, that a database "overloaded" and that the company was scrambling to get new machines working.
It's believed to be one of Facebook's longest-ever outages.
A link in the error message users saw earlier in the day took users to the Facebook Help Center. The post explains that Facebook is making improvements to the database that the account is stored on, but user's account won't be affected.
The post also clarifies that Facebook doesn't do site maintenance for all accounts at the same time, so some users will be able to access the site while others can't.
Personal accounts and Facebook pages seem to be equally affected by the supposed maintenance. Users have reported that they can't comment on posts by pages whose accounts are undergoing maintenance.
Users have also reported that they are unable to log into their Instagram accounts. With both apps down, many users are going to Twitter to express their frustration.