[jump] the (tracks|rails)

to unexpectedly switch from the planned path

The idiom "jump off the tracks" originated from the literal sense of a train derailing, symbolizing an unexpected and often chaotic deviation. Metaphorically, it conveys a similar sense of unexpected shift or disruption in plans, actions, or thoughts. It's often used to highlight a situation where something unexpectedly deviates from the intended path. Additionally, it can be applied to individuals who suddenly shift from one activity to another.

The project seemed promising, but it jumped the rails when unexpected challenges arose.
The company's expansion plans jumped the rails due to unforeseen economic downturns.
The political campaign jumped the tracks after a series of controversial statements by the candidate.
The peaceful protest jumped the tracks when a small group started engaging in disruptive behavior.
The team's well-organized project suddenly jumped the tracks when unforeseen challenges arose.

(of a train) to accidentally leave the railroad

The old steam locomotive jumped the tracks during the historic reenactment, causing a brief pause in the festivities.
The intense storm and flooding caused several trains to jump the tracks, disrupting the railway schedule.
Thankfully, the high-speed train had safety mechanisms in place that prevented it from jumping the tracks during the emergency stop.
The investigation revealed that a faulty switch system was responsible for the commuter train jumping the rails unexpectedly.
The maintenance crew worked diligently to ensure that the aging rail infrastructure wouldn't lead to trains jumping the rails.