collapses after 30 minutes into a slap-happy series of adolescent violence 
(ROOT (VP (VBZ collapses) (PP (IN after) (NP (CD 30) (NNS minutes))) (PP (IN into) (NP (NP (DT a) (ADJP (NN slap) (HYPH -) (JJ happy)) (NN series)) (PP (IN of) (NP (JJ adolescent) (NN violence)))))))
(ROOT (VP (VBZ ) (PP (IN ) (NP (CD ) (NNS ))) (PP (IN ) (NP (NP (DT ) (ADJP (NN ) (HYPH ) (JJ )) (NN )) (PP (IN ) (NP (JJ ) (NN )))))))