[CaptSkip]

That would've been the seismological observatory at OU, about 30 miles south in Norman. I believe the official spin on the story was that the second wave was an echo caused by a substratum of stone.

My house and body were not underground, and there were TWO separate explosions I heard, and two separate blast waves that hit my house, traveling across the flat Oklahoma prairie. Period.

[Leatherneck_MT]

My house and body were not underground, and there were TWO separate explosions I heard, and two separate blast waves that hit my house, traveling across the flat Oklahoma prairie. Period.

I believe you Skip, too many people that day heard 2 distinct explosions for it to have been their imagination.