Congress killed the idea.
( Congress ( ( killed ( the idea ) ) . ) )
(ROOT (S (NP (NNP Congress)) (VP (VBD killed) (NP (DT the) (NN idea))) (. .)))
Congress vetoed it for safety concerns.
( Congress ( ( ( vetoed it ) ( for ( safety concerns ) ) ) . ) )
(ROOT (S (NP (NNP Congress)) (VP (VBD vetoed) (NP (PRP it)) (PP (IN for) (NP (NN safety) (NNS concerns)))) (. .)))