So it was traumatic.
( So ( it ( ( was traumatic ) . ) ) )
(ROOT (S (IN So) (NP (PRP it)) (VP (VBD was) (ADJP (JJ traumatic))) (. .)))
It was something that was traumatic. 
( It ( ( was ( something ( that ( was traumatic ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBD was) (NP (NP (NN something)) (SBAR (WHNP (WDT that)) (S (VP (VBD was) (ADJP (JJ traumatic))))))) (. .)))