The window crack man arrived at the highrise to take a look at our window. Poor installation he said. Maybe a screw fixing point. Might have been ok for ever, but it was the tinting wot done it in. The temperature difference was too much when the sun was on half the window and it broke at a vulnerable point. Of course I was quite right on several fronts, least of all that the crack would get worse. Yes, owners corporation will pay, maybe even for the re tinting. Meanwhile Copperwitch's previous comment worries me whenever the wind blows.