Yeah, you got left hanging, not good.
Were there any trees present at any time you know of near the leaking area?
Something like you describe needs to be repaired from the inside. Finding the leak from inside will determine what method is best to repair. I suspect it will require excavation when the area is found and fixed. The process is similar to an upside down wedding cake, but depends on location.

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May God be with the Overton's Family.