(S (S (NP (BASENP (DT The) (JJ 45-pound) (NN bomb)) (PRN (COMMA ,) (SBAR (WHNP (WDT which)) (S (VP (VBD was) (VP (VBN placed) (PP (IN under) (BASENP (DT a) (NN stairwell))))))) (COMMA ,))) (VP (VBD exploded) (NP (NP (BASENP (RB around) (NN 1:30) (NN am)) (BASENP (JJ local) (NN time))) (PRN (LRB -LRB-) (NP (BASENP (NN 0330)) (BASENP (NN UTC))) (RRB -RRB-))))) (PERIOD .))