No blaze spawners spawned in my nether fortress

When I created a new world I started it off trying to do a speedrun and once I got my obsidian and went into the nether I was exploring for a bit and then a few hundred blocks away was the fortress but when I went in it it was just mainly hallways and there was 2 chests in the whole thing and once I was out of the hallways I went looking for the blaze spawners then I found the blaze spawner area but there was no spawner 

The seed is -877337642

And the coordinates are 255 77 -286