I seem to recall the police bombing their own employers in Philadelphia, PA some 25 years ago with similar results and more fatalities.
Not insinuating anything, just a reminder.
And yes, a natural gas leak is very capable of producing a kaboom of this magnitude.
Second grade teacher and husband killed
this story indicating the home that exploded was vacant http://dmnewsi.com/2012/11/11/teacher-husband-killed-in-indiana-blast/