Heart of Y'shaarj

I wonder how did the Titans destroy Y'shaarj.

That bit is very unclear it's only known that when he was destroyed the land was cursed with the sha, that made the titans decide to imprison Yogg-Saron, C'Thun and N'Zoth.

According to the WarCraft III manual there were originally 5 old gods if the fifth does exist no one knows.

Hmm i read the manual. It's very unprecise about these beings. Too bad

The Old Gods and the Titans are very unknown subjects I was hoping to get more information on them in the book Dawn of the Aspects but it contained none.