Facebook has blamed the faulty configuration changes made to its routers for the 6-hour global outage on Monday.
“Our engineering teams have learned that configuration changes on the backbone routers that coordinate network traffic between our data centers caused issues that interrupted this communication. This disruption to network traffic had a cascading effect on the way our data centers communicate, bringing our services to a halt,” Facebook said in a blog post.
Facebook, WhatsApp and Instagram services were down for the majority of users on Monday night for nearly 6 hours. Several users took to Twitter to report an outage on these platforms.
However, several Facebook employees who declined to be named told Reuters earlier that they believed that the outage was caused by an internal mistake in how internet traffic is routed to its systems.
“We want to make clear at this time we believe the root cause of this outage was a faulty configuration change,” Facebook said in the blog.
The Facebook outage is the largest ever tracked by web monitoring group Downdetector. The outage came as a second blow to the social media giant in as many days after a whistleblower on Sunday accused the company of repeatedly prioritizing profit over clamping down on hate speech and misinformation.
In addition to the disruption to people, businesses and others that rely on the company’s tools, Facebook CEO Mark Zuckerberg took a financial hit.
Fortune’s billionaire tracking website late Monday said Zuckerberg’s personal fortune plunged by nearly $6 billion from the prior day to land at just under $117 billion.