It is quite possible Jarrah knew of the success of the assault on the World Trade Center.
( It ( ( is ( quite ( possible ( Jarrah ( ( knew ( of ( ( the success ) ( of ( the assault ) ) ) ) ) ( on ( the ( World ( Trade Center ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ is) (ADJP (RB quite) (JJ possible) (SBAR (S (NP (NNP Jarrah)) (VP (VBD knew) (PP (IN of) (NP (NP (DT the) (NN success)) (PP (IN of) (NP (DT the) (NN assault))))) (PP (IN on) (NP (DT the) (NNP World) (NNP Trade) (NNP Center)))))))) (. .)))
It is likely that Jarrah was aware of the incident at the World Trade Center.  
( It ( ( ( is likely ) ( that ( Jarrah ( ( was ( aware ( of ( the incident ) ) ) ) ( at ( the ( World ( Trade Center ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ is) (ADJP (JJ likely)) (SBAR (IN that) (S (NP (NNP Jarrah)) (VP (VBD was) (ADJP (JJ aware) (PP (IN of) (NP (DT the) (NN incident)))) (PP (IN at) (NP (DT the) (NNP World) (NNP Trade) (NNP Center))))))) (. .)))