Fortnite is completely down right now for all platforms, with Epic Games taking to the official Twitter account for Fortnite announcing that they were taking the Fortnite servers down for "emergency maintenance".
We're bringing the servers offline for emergency maintenance. We apologize for this inconvenience. We currently have no ETA on when servers will be back up. Stay updated with our status page here: https://t.co/3y0X6buriO— Fortnite (@FortniteGame) April 12, 2018
This is a huge deal as Fortnite is one of the most-played games on the planet right now, with the developer acknowledging that people were having issues logging in, and now the servers are dead. Matchmaking was also affected, or "degraded" due to these account issues.