We don't know (or do we) that the bomb-making materials being detonated were coming from the kid's apartment or some other apartment in the building, which apparently housed muslim students, too.
I've missed the link where the Triangle president spoke about his frat brother. So you know where it is?
The explosive materials that were detonated last night (Sun night) were taken out of Hinrichs' apartment in a black duffel-type bag a little while earlier.
There are some twilight photos taken of the bomb squad removing it on this blog:
http://www.ottergoose.net/