How much explosive charge does a typical large rocket carry and what's left after it destructs? There are a lot of big, heavy metal components and it seems unlikely that they all just vaporize. The self destruct gets rid of all the fuel and oxidizer but there must be quite a few big heavy chunks raining down.
It's actually not much explosive, typically just a linear charge to "unzip" the component. Aerodynamic stress does the rest.
Depending how high the failure occurs, some of the components will burn up in the atmosphere, others won't. Launches are usually directed over water so falling components won't impact land--rockets are launched eastward from KSC and southward from Vandenburg, for example. Notice to mariners is given well in advance to avoid these areas.
Shuttle SRBs came down on parachutes, while the Saturn V S-1C stage just fell into the ocean intact.