OK YOU PROBLY WON'T BELIVE ME BUT I SWEAR TO GOD THIS IS REAL!
I was just mining out a tunnel for my mine cart rails but when I came back the roof of my house was GONE!
I was playing on peaceful so no creepers or ender men could destroy it and this was on single player so no-one could have got on so I have no idea what it was... I can only think that hero brine destroyed it! I know this sounds crazy but PLEASE believe me! THIS IS NOT A JOKE!