Broken glass mystery

First trip away this year, arrived on site, got in van to be greeted by a pile of shattered toughened glass in front of the Thetford Midi Prima cooker. Oven, grill, and lower cupboard glass doors plus hob cover were all intact. On opening oven door realised that the inner door sheet of glass was missing. Worked out that this slides in from the top and is held in place by two metal tabs at the base. After breaking into a thousand pieces they somehow found their way out under the main door onto the floor. 

Not sure how it could have shattered, as nothing sharp to knock against it in the oven - maybe it was under stress in its metal fastenings and a pothole shocked it into breaking. I remember hitting one jarring nearside hole which was unavoidable due to HGV coming the other way. Just shows how bad our roads are as have been towing this van for 10 years.

Also suffered a cracked windscreen on the same trip - loose stones on tar road repair, 20mph limit, loony comes the other way at about 50mph, big bang as stone bounces off bonnet into screen. Quite enough for one trip!