(S (S (S (BASENP (DT The) (NNS deaths)) (VP (VBD were) (VP (VBN caused)))) (SBAR (RB mainly) (SBAR (IN because) (S (BASENP (DT some) (NNS shanty-houses)) (VP (VBD collapsed) (PP (IN under) (BASENP (NN rain) (CC or) (NN mud)))))))) (PERIOD .))