Nokia Lumia 520 unorthodox screen crack?

[WPCentral Question]

I have a Lumia 520 that had a small dink on the upper right hand corner with the tiniest crack on it. I was using it like I do normally, and then 5 minutes after I put it in my pocket, a long crack is diagonally across my screen. Bearing in mind this had a case on, I was wondering what caused that crack to grow so big. It's rendered the bottom half of the crack of touchscreen unusable and I don't have the money to repair or replace it. So what should I do?

 

[Asskickulater]

Well, it was chipped, once you damage glass to the point of cracking/chipping, the glass will crack along the grain very easily, more than likely you flexed it a bit while it was in your pocket and under the stress the crack worked its way down, the only thing you can do is replace the glass or buy a new phone.