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