By 9:08, the mission crew commander at NEADS learned of the second explosion at the World Trade Center and decided against holding the fighters in military airspace away from 
( ( By 9:08 ) ( , ( ( ( the ( mission ( crew commander ) ) ) ( at NEADS ) ) ( ( ( ( learned ( of ( the ( second explosion ) ) ) ) ( at ( the ( World ( Trade Center ) ) ) ) ) and ) ( decided ( against ( ( ( holding ( ( the fighters ) ( in ( military airspace ) ) ) ) away ) from ) ) ) ) ) ) )
(ROOT (S (PP (IN By) (NP (CD 9:08))) (, ,) (NP (NP (DT the) (NN mission) (NN crew) (NN commander)) (PP (IN at) (NP (NNP NEADS)))) (VP (VP (VBD learned) (PP (IN of) (NP (DT the) (JJ second) (NN explosion))) (PP (IN at) (NP (DT the) (NNP World) (NNP Trade) (NNP Center)))) (CC and) (VP (VBD decided) (PP (IN against) (S (VP (VBG holding) (NP (NP (DT the) (NNS fighters)) (PP (IN in) (NP (JJ military) (NN airspace)))) (PRT (RP away)) (PP (IN from)))))))))
The second explosion at the world trade center happened after 9:30am.
( ( ( The ( second explosion ) ) ( at ( the ( world ( trade center ) ) ) ) ) ( ( happened ( after ( 9:30 am ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ second) (NN explosion)) (PP (IN at) (NP (DT the) (NN world) (NN trade) (NN center)))) (VP (VBD happened) (PP (IN after) (NP (CD 9:30) (RB am)))) (. .)))