90% of the debris burns up in the atmosphere. The remaining 10% -- who knows where they end up, but it is said that it's unlikely that the debris hit anything important.

This isn't the first time something like this happened. When NASA's SkyLab fell to earth in 1979, an Australian town fined them $400 -- for littering. https://science.slashdot.org/story/09/07/14/1556228/nasas-sk...