I'm sorry - that "larger problem" it was recycled foam.
Columbia could have survived if foam hit a different part of it. But the point remains - and you omitted it from your posts - EPA regulations killed both Columbia and Challenger.
You missed my point, which was easy to do since I really didn't explain it very well. My point is that perfectly fine non-recycled BX-250 foam fell off of the bipod strut of 10% of flights that were observed by the CAIB. 80% of flights had other foam fall off (much of that was BX-250).
The EPA didn't kill those astronauts any more than the Russians killed the astronauts of Apollo 1. NASA's failure to determine the danger of the foam (recycled, freon, on non-freon) is what killed the astronauts. If recycled BX-250 was too dangerous, NASA always could have canceled the launch. They didn't. There are many agencies and regulations that sometimes conflict with what NASA wants to do. It is the job of NASA to communicate with them and work around the problems, and if necessary alter their programs in a safe manner. If I had to assign blame for the loss of Columbia, I would put 0.01% (at most) at the hands of the EPA and 99.99% at the hands of NASA.
EPA regulations also contributed to the collapse of the World Trade Center.
You're not hearing about it for the same reasons - Gang Green kills people, and the TRUTH.