When I was at accident investigation school, I read an edited transcript that I was told was from the actual CVR tape of the Space Shuttle Challenger. It was chilling--they were alive after the explosion. The shuttle commander called for emergency checklists--the co-pilot explained that there was no orbiter to run the checklists on. Judith Resnik tried to comfort Christie McAllif--who then fainted. One of the crewmember then led them in the 23rd Psalm.
I believe the transcript was legitimate--because our instructor later told us how NASA had spent much time and $$$ researching an "escape" mechanism for the crew compartment--but all was abandoned because the solutions were not feasible due to weight and other restrictions.
I am not a shuttle expert by any means--so perhaps someone here knows more about it--but I do not believe an escape was possible for them.
The warnings on the debris are just words out of their "contingency procedure". There is no way that any Nitrogen Tetroxide or Monomethyl Hydrazine could survive the re-entry heat.
It's too bad the the OPS recorders and especially the OEX recorder will not survive the re-entry either. The OEX recorder has the strain gage and temperature data on the wings, elevons, and fuselage.