
Big Thunder Mountain Railroad at the Magic Kingdom (MK) has been down now for over 5 hours now, going down just after MK opened this morning.
Whilst visiting MK today, Mike of Blog Mickey noticed that a train was still on the track, “signalling” prolonged downtime that likely won’t be fixed today, according to Cast Members the Blog Mickey owner and writer spoke with.

Guests who have FastPass+ for the attraction are being offered alternative attraction choices automatically within the My Disney Experience app and via email.
Source: Blog Mickey