10" joists reduced to 2"

We took out the 'modern' bathtub--less than 8 years old--since it was leaking pretty bad. We discovered that they had cut almost 8" out of the 10" floor joists!! Unbelievable, really the worst damage we are finding to the building are the repairs done in the past ten years. The original work from 100 years ago is in good shape. A good cautionary tale for our own repairs!