See, even on a holiday, TM gets things up and running in short order. It sounds like a tower malfunction that was quickly fixed. In heavily congested areas, if a tower goes down, there is usually another nearby tower that can pick up the slack - so you'd never notice.
All kinds of things can bring a tower down. Technical failure. Physical failure like wind etc. Failure in the line that connects the tower with the system. Failure in the electrical source that powers the tower.