avoidable — Something that is avoidable can be prevented from happening.
unscheduled — a plan of procedure, usually written, for a proposed objective, especially with reference to the sequence of and time allotted for each item or operation necessary to its completion: The schedule allows three weeks for this stage.
derailed — Cause (a train or trolley car) to leave its tracks accidentally.
detained — Simple past tense and past participle of detain.
sidetracked — any railroad track, other than a siding, auxiliary to the main track.
