Shortly after stepping out on the bridge, Jon felt the entire walkway narrow.
( ( Shortly ( after ( ( stepping out ) ( on ( the bridge ) ) ) ) ) ( , ( Jon ( ( felt ( ( the ( entire walkway ) ) narrow ) ) . ) ) ) )
(ROOT (S (PP (RB Shortly) (IN after) (S (VP (VBG stepping) (PRT (RP out)) (PP (IN on) (NP (DT the) (NN bridge)))))) (, ,) (NP (NNP Jon)) (VP (VBD felt) (S (NP (DT the) (JJ entire) (NN walkway)) (ADJP (JJ narrow)))) (. .)))
Shortly after stepping out on the bridge, Jon felt the wobbly walkway narrow.
( ( Shortly ( after ( ( stepping out ) ( on ( the bridge ) ) ) ) ) ( , ( Jon ( ( felt ( ( the ( wobbly walkway ) ) narrow ) ) . ) ) ) )
(ROOT (S (PP (RB Shortly) (IN after) (S (VP (VBG stepping) (PRT (RP out)) (PP (IN on) (NP (DT the) (NN bridge)))))) (, ,) (NP (NNP Jon)) (VP (VBD felt) (S (NP (DT the) (ADJP (JJ wobbly)) (NN walkway)) (ADJP (JJ narrow)))) (. .)))