Need advice on live rock formation

[Dabzie]

So this is my first marine tank. its been going 3/4 months now no problems untill last night it's 450l 5ft long. I found my copperband butterfly ontop of my internal filter dead but as dry and hard as they come. i have no idea how it has managed to get on top of this as the water level is a cm below the top and there is no way it swam on top of it or a current took it on top. i am wondering if it managed to somehow jump on top to use as a form of hiding place, which has made me question my liverock set up. i am added a picture so all can see. there is roughly 45kg and it it spaced out in the middle of the tank with plenty of space behind it. i am wondering if i should move the rock back towards the glass to create more hiding places between the glass and the rock, there is plenty of spaces for my damsels to hide and my tang hide's between the rock and skimmer at night. And now i look it it there dont seem to be many places for larger fish with the current set up.also at the mo i have one powerhead facing behind the rock and one across the front would this be advisable?

[tcamos]

I don't think the rockwork is the issue. There are plenty of hiding places in there for the fish. Where in the tank is the location you found the dead fish? I can't tell from the photo.

[Dabzie]

On the right hand side in the internal filter. It was on top of that

[Nate_Bro]

I would just say it jumped, I have lost my share of fish from jumping incidents

the fish could have gotten spooked then jumped or jumped for another reason..