In the Deep Roads, during Trespasser, you can find the fresco depicting the destruction of a Titan and a Veilfire rune which describes how the Titans were sealed underground.
These passages are important:
The vision grows dark. An aeon seems to pass. Then the runes crackle, as if filled with an angry energy. (Theories say that the Titans probably created the Blight to defend themselves against the elves mining their bodies for lyrium)
A new vision appears: elves collapsing caverns, sealing the Deep Roads with stone and magic. Terror, heart-pounding, ice-cold, as the last of the spells is cast. (The elves seal the Deep Roads to stop the Blight from keep reaching the surface, basically locking the Titans and the dwarves with the very plague the Titans created as a self-defense mechanism)
âWhat the Evanuris in their greed could unleash would end us all. Let this place be forgotten. Let no one wake its anger. The People must rise before their false gods destroy them all.â
Considering what the ancient elves did to the Titans and the dwarven people, I doubt the Titans are that willing to forgive the Elvhen and carry on with their lives. Also, how would Orzammar and Kal-Shirok react to such a revelation?
They will learn about this, itâs inevitable, and it will be hard to convince the dwarves that there is no need to hate and attack the elves.
The downfall of their civilization has practically been caused by the ancient elves, whose acts had consequences that ruined the dwarves for generations and twisted their entire society (fear of the surface because Elgarnânanâs sun was up there waiting to burn them, cast system, severed link with their symbiotic protectors and the Fade/magic/dreams, poverty, darkspawn raids and the Blight).
The Titans have not forgotten this and the dwarves are basically their children, so the offense is even greater. Even though the one in the Descent calmed down after finally reuniting with a dwarf after millennia of loneliness, pain, and dark slumber, it doesnât mean it isnât angry or willing to do something bad, catastrophic, or âviolentâ (like shaking the ground or rising). Also, it was awakened by the Breach and itâs probable even the other Titans sensed the sundered Veil and managed to wake up.
And speaking of rising, Drakon said that his prophetic vision showed him this:
Seven times seventy men of stone immense
Rose up from the earth like sleepers waking at the dawn,
Crossing the land with strides immeasurable,
And in the hollows of their footprints
Paradise was stamped, indelible.
