(S (S (SBAR (S (PP-SBJ (BASENP (NN 調査)) (IN が)) (VP (VP (VP (VBO 行わ) (VP (VBV れ))) (INTE て)) (VP (VB いる)))) (INCON が)) (COMMA 、) (S (PP-SBJ (SBAR (SBAR (S (PRN (S (PP-SBJ (BASENP (NN 何)) (IN が)) (VP (BASENP (NN 原因)) (MDV で)))) (S (PP-SBJ (BASENP (NN 炎)) (IN が)) (VP (VBV 上がっ) (VP (MD た))))) (NN の)) (INFKB か)) (IN は)) (COMMA 、) (VP (ADVP (ADVP (RB すぐ) (IN に)) (IN は)) (VP (PP (BASENP (NN 明らか)) (IN に)) (VP (VBO なら) (VP (MDV なかっ) (VP (MD た)))))))) (PERIOD 。))
調査 が 行わ れ て いる が 、 何 が 原因 で 炎 が 上がっ た の か は 、 すぐ に は 明らか に なら なかっ た 。
It was not immediately clear what caused the blaze , although an investigation is underway .