The hijackers were wearing red bandanas, and they forced the passengers to the back of the aircraft.
( ( ( ( ( ( The hijackers ) ( were ( wearing ( red bandanas ) ) ) ) , ) and ) ( they ( ( forced ( the passengers ) ) ( to ( ( the back ) ( of ( the aircraft ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (DT The) (NNS hijackers)) (VP (VBD were) (VP (VBG wearing) (NP (JJ red) (NNS bandanas))))) (, ,) (CC and) (S (NP (PRP they)) (VP (VBD forced) (NP (DT the) (NNS passengers)) (PP (TO to) (NP (NP (DT the) (NN back)) (PP (IN of) (NP (DT the) (NN aircraft))))))) (. .)))
The passengers were allowed to remain in their seats by the hijackers.
( ( The passengers ) ( ( were ( allowed ( to ( ( remain ( in ( their seats ) ) ) ( by ( the hijackers ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS passengers)) (VP (VBD were) (VP (VBN allowed) (S (VP (TO to) (VP (VB remain) (PP (IN in) (NP (PRP$ their) (NNS seats))) (PP (IN by) (NP (DT the) (NNS hijackers)))))))) (. .)))