MacBook Pro Cracked Screen

I'm baffled. I treat my electronics very well simply because I spend a lot of money on them and want them to last a long time. However, I went to use my computer this morning and at first noticed a scratch on my screen, after further investigation there is a crack in the top portion of my screen from one side to the other. My question is since I've had this particular MacBook less then a year, would that be covered for replacing? If not, how much would one cost?

I'm really confused as to how this even happen.

Thanks!