Lightning strikes the tower's crown, the crown flies off, two figures fall. It is the harshest image in the deck and there is not much soft reading available.
The Tower usually marks a sudden collapse. Fired, left, an accident, a side of someone you trusted that you had not seen. What these share is not that there was no warning but that the warning went unread. The tower was already cracked; the lightning was the occasion.
The one consolation is that what falls was generally not sound. Well-built things do not come down. The relationship held together by force, the business with numbers nobody looked at, the plan you knew was wrong. Only afterwards do you see how much effort it took to keep it standing.
Reversed, read it as not fallen yet. You already know, and you are postponing. Or you are just holding on, hoping nobody touches it. That leaves one real choice: wait for the collapse, or bring it down yourself. Both hurt, but the second lets you pick the timing and the manner. That difference is larger than it sounds.
The Tower does not have to be read as pure disaster. Something does collapse, but the point is that it was badly built to begin with. It looks sudden because the cracks were there long before anyone looked. So the card announces a loss and, at the same time, shows you what you had been holding up.
Beside the Star, what comes after the collapse is already visible. With the Devil, the collapse is what breaks the chain. The Tower is frightening alone and usually bearable once you read the card that follows.