{hachi-kai karaderenaku} natte-iru... 8階から出れなくなっている・・・ [It] has become so that {[we] can't leave the eighth floor}. [We] are no longer able to leave the eighth floor.
hachi-kai kara derenai - "[we] can't leave the eighth floor."
n... {{hachi-kai kara derareru} you ni} natta-n-desu ka? ん・・・8階から出られるようになったんですか? Hmm... did [it] become {so [that] {[we] can leave the eighth floor}}? Hmm... can we leave the eighth floor now?
hachi-kai kara derareru - "[we] can leave the eighth floor."
derareru - potential form (including ra ら) of deru 出る.
zan'nen nagaramada muri-ppoi 残念ながらまだ無理っぽい Unfortunately [it] seems to be still impossible.