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)))) (. .)))
The walkway widened soon after Jon stepped on the bridge.
( ( The walkway ) ( ( widened ( soon ( after ( Jon ( stepped ( on ( the bridge ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN walkway)) (VP (VBD widened) (SBAR (RB soon) (IN after) (S (NP (NNP Jon)) (VP (VBD stepped) (PP (IN on) (NP (DT the) (NN bridge))))))) (. .)))