As pointed out in the movie by Professor Ping, life begins to dissolve into nothingness, with some victims getting holes in their bodies. There is no way to reach Sogo from the Labyrinth and is considered inescapable.
The Magmous, upon which Sogo is built, also runs underneath the Labyrinth. This is proven when The Great Tyrant, in a vein attempt to destroy Durand Durand who betrayed her, releases the Magmous and it erupts in the Labyrinth and covers it.
The Labyrinth was destroyed as was Sogo, but it is unclear if any other part of Lythion was destroyed, though it is very unlikely.