He fled in his car when cops arrived and led them on a chase that ended in the massive crash.
( He ( ( ( fled ( in ( his car ) ) ) ( when ( cops ( ( arrived and ) ( ( led them ) ( on ( ( a chase ) ( that ( ended ( in ( the ( massive crash ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP He)) (VP (VBD fled) (PP (IN in) (NP (PRP$ his) (NN car))) (SBAR (WHADVP (WRB when)) (S (NP (NNS cops)) (VP (VP (VBD arrived)) (CC and) (VP (VBD led) (NP (PRP them)) (PP (IN on) (NP (NP (DT a) (NN chase)) (SBAR (WHNP (WDT that)) (S (VP (VBD ended) (PP (IN in) (NP (DT the) (JJ massive) (NN crash))))))))))))) (. .)))
The cops set off in pursuit until a traffic accident happened.
( ( The cops ) ( ( ( ( set off ) ( in pursuit ) ) ( until ( ( a ( traffic accident ) ) happened ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS cops)) (VP (VBD set) (PRT (RP off)) (PP (IN in) (NP (NN pursuit))) (SBAR (IN until) (S (NP (DT a) (NN traffic) (NN accident)) (VP (VBD happened))))) (. .)))