Shattered atrium 10 foot tall dual pane glass window

Has anyone had their large glass panel shatter without an apparent reason? 

When I arrived from work today I found my atrium 10 foot tall window shattered (outside panel is shattered, inside panel is intact). I know for a fact that that nobody enter the atrium (it would trigger our alarm system) and that the place where the shattering started was not hit with anything (surface is perfect). Since we have polished concrete floors, we are able to see the slab cracks. And the slab crack coincides with the shattering origin, so we believe it is because the slab moved just enough to crack the window. 

This window was replace in early 2016 and it used to be single pane. We had Palo Alto Glass replace it with a dual panel window for safety reasons and to get better insulation. Any tips on how to deal with this situation would be appreciated.