http://www.parabolicarc.com/2016/09/01/elon-musk-falcon-9-explosion-originated-oxygen-tank-fueling/ Looking at the video of the explosion: http://www.parabolicarc.com/2016/09/01/video-spacex-falcon-9-explosion/ it appeared to me that the flash was centred near where the lines were attached to the upper stage. 73s Bernhard VA6BMJ @ DO33FL