(S (S (BASENP (NN Four) (NNS workers)) (VP (VBP are) (VP (ADVP (RB still)) (VP (VP (VBN hospitalised) (PP (IN after) (BASENP (DT the) (NN explosion)))) (COMMA ,) (S (BASENP (NN three)) (PP (IN in) (BASENP (JJ critical) (NN condition)))))))) (PERIOD .))