Lucky indeed! Think of the uproar if the tree managers had been able to do more (remove and be crucified) than WARN the residents. Houses and other property could have been damaged or destroyed, people and/or pets injured or killed . . . The "rot" is a terminal disease, eating away at the structural interior while the tree's living cells just under the bark remain "perfectly healthy." A plant physiologist/pathologist, a dendrochornologist, a physicist, and perhaps a structural engineer should be called in to provide a thorough analysis of the factors that contributed to the tree's progressive decline in strength/structural resistance--structural failures occur when load or the sum of physical forces exceed resistance. The tree's very "health" also may have contributed to the effective force by growing taller (longer lever arm = exponentially-increasing force) and heavier. Tree condition, context, and failure assessment study.

I was there

That's an omen.