The property owner attempted to clear the obstruction by repeated use of the plunger and the use of an economy closet auger. This did not resolve the issue given the size of the obstruction in the toilet trapway.
When we arrived to perform the task of the clogged toilet we performed a short diagnostic test of the following:
Ran water down the drain of the adjacent tub
Ran water down the drain of the adjacent lavatory
If either of those two fixtures would of created a disturbance of the water in the trapway of the toilet, that would of led to the obstruction of the drain line, not the toilet in question.
Lateral branches tie into the larger piping that serves the toilet in the bath group it serves. When more than one fixture is affected in a clogged/backed up scenario, this implies that the location of the clog is beyond the toilet, requiring a longer "reach" to break loose the obstruction.