All understood the plane had been hijacked.
( All ( ( understood ( ( the plane ) ( had ( been hijacked ) ) ) ) . ) )
(ROOT (S (NP (DT All)) (VP (VBD understood) (SBAR (S (NP (DT the) (NN plane)) (VP (VBD had) (VP (VBN been) (VP (VBN hijacked))))))) (. .)))
Everybody knew about the hijacking.
( Everybody ( ( knew ( about ( the hijacking ) ) ) . ) )
(ROOT (S (NP (NN Everybody)) (VP (VBD knew) (PP (IN about) (NP (DT the) (NN hijacking)))) (. .)))