https://www.mercurynews.com/2021/10/06/facebook-says-outage-was-caused-by-error-during-routine-maintenance/

LONDON (AP) — The global outage that knocked Facebook and its other platforms offline for hours was caused by an error during routine maintenance, the company said.

Santosh Janardhan, Facebook’s vice president of infrastructure, said in a blog post that Facebook, Instagram and WhatsApp going dark was “caused not by malicious activity, but an error of our own making.”