until it goes off the rails in its final 10 or 15 minutes 
(ROOT (SBAR (IN until) (S (NP (PRP it)) (VP (VBZ goes) (PP (IN off) (NP (DT the) (NNS rails))) (PP (IN in) (NP (PRP$ its) (JJ final) (QP (CD 10) (CC or) (CD 15)) (NNS minutes)))))))
(ROOT (SBAR (IN ) (S (NP (PRP )) (VP (VBZ ) (PP (IN ) (NP (DT ) (NNS ))) (PP (IN ) (NP (PRP$ ) (JJ ) (QP (CD ) (CC ) (CD )) (NNS )))))))