(S (S (BASENP (DT The) (NN bus)) (VP (VBD had) (VP (VBN been) (VP (VP (VP (VBG taking) (BASENP (DT the) (NNS tourists))) (ADVP (RB home))) (PP (IN after) (NP (BASENP (DT a) (NN trip)) (PP (TO to) (BASENP (NNP Bulgaria))))))))) (PERIOD .))