That has to do with the size of the debris. In a back of the envelope approximation, an object 10x as big in every dimension has 1000 times the mass and experi

That has to do with the size of the debris. In a back of the envelope approximation, an object 10x as big in every dimension has 1000 times the mass and experiences 100 times the air resistance. And therefore flies about 10 times as far. (Only an approximation, there are other factors. For example gravity acts the same on both.) Nobody anticipated the debris would include large chunks of concrete. And therefore it was able to travel much farther than expected.