Before you read this thread make sure you have read up on what the Dragon Breaks are or could be. It is very confusing and all of this that I'm suggesting may be completely negated by someone who understands the lore better than I do.

"The Apotheosis of Alessia. The earlier record says that Shezarr, the missing sibling god of the Eight Divines, arrives at the White Gold Tower in the Imperial City and transforms the dying Alessia into the first of the Cyrodiilic saints. Thus Empress Alessia becomes the first gem in the Amulet of Kings. While the book of Trials of Alessia states that Akatosh made a covenant with Alessia, he promises to protect the Empire of Men from the Daedric Princes of Oblivion as long as she and her descendants wear the Amulet of Kings and the magical dragonfire burn. This makes an interesting yet controversial connection (as revealed by Michael Kirkbride) that Akatosh is Shezarr/Lorkhan. Scholars are still debating this revelation to this day.

"So long as the Blood of the Dragon runs strong in her rulers, the glory of the Empire shall extend in unbroken years. But should the dragonfires fail, and should no heir of our joined blood wear the Amulet of Kings, then shall the Empire descend into darkness, and the Demon Lords of Misrule shall govern the land."
- from TRIALS OF ST. ALESSIA."

- Taken from http://www.imperial-library.info/history/1.shtml page under 1E 266

"R'leyt-harhr, Khajiit, Tender to the Mane:

"Do you mean, where were the Khajiit when the Dragon Broke? R'leyt tells you where: recording it. 'One thousand eight years,' you've heard it. You think the Cyro-Nordics came up with that all on their own. You humans are better thieves than even Rajhin! While you were fighting wars with phantoms and giving birth to your own fathers, it was the Mane that watched the ja-Kha'jay, because the moons were the only constant, and you didn't have the sugar to see it. We'll give you credit: you broke Alkosh something fierce, and that's not easy. Just don't think you solved what you accomplished by it, or can ever solve it. You did it again with Big Walker, not once, but twice! Once at Rimmen, which we'll never learn to live with. The second time it was in Daggerfall, or was it Sentinel, or was it Wayrest, or was it in all three places at once? Get me, Cyrodiil? When will you wake up and realize what really happened to the Dwarves?" "


-Taken from http://www.imperial-library.info/mwbooks/dragonbroke.shtml

If Lorkhan is indeed the old Smaug himself, Akatosh, then when the Dwemer struck the heart is it not possible that they caused a Dragon Break and erased themselves from existance by striking the heart of the time god?

It's kind of hard for me to see how you came to this Dragon Break conclusion just from these two quotes, but the thing is we know what happened to the Dwarves.

The whole point of R'leyt-harhr's final statement is that he is refuting the common notion of what the people of Tamriel think happened to the Dwarves. That notion is that Nerevar along with his Chimer brothers killed them all. We know that isn't true but it seems the people of Tamriel don't know that. What R'leyt-harhr is suggesting is that the Numidium was a big part of what happened to the Dwarves, which it was.

Dragon Breaks are events where Time caters to the apotheosis of a god that didn't exist beforehand; it bends so that a god, who must "always" exist to be called a "god," will always have existed.

the dwemers dropped the dragon and it broke they said it wasnt us

It doesn't follow that striking the Heart of a Time God will make you disappear.

You're onto something about the Numidium alright, but this isn't it.

Well the whole point of the post was about Dragon Breaks. Vehk used the power of the heart to cause a Dragon Break and write himself into the history of the Dunmer/Chimer as their god. If the heart can be harnessed to change history in such a drastic way then who is to say that the Dwemer, who struck the heart in what sounds like a rather barbaric way, could of caused the same event but without controlling it an unexpected event occurred and erased the Dwemer's existence.

I bring this up because Dragon Breaks are such a mysterious thing. I think the most likely scenario is that the Dwemer didn't go far. I think they just became part of the Numidium but I still think about this possibility.