(S (S (PP-SBJ (NP (S-REL-NSBJ (VP (PP-OBJ (NP (PP (BASENP (NN 火山)) (IN の)) (NP (PP (BASENP (NN 北西)) (IN の)) (NN 斜面))) (IN を)) (VP (VBV 流れ落ち) (VP (MD た))))) (NN 火砕流)) (IN は)) (VP (PP (BASENP (NN 後)) (IN に)) (VP (PP-OBJ (NP (PP (BASENP (NN 破壊)) (IN の)) (NN 道)) (IN を)) (VP (VBV 残し) (VP (MD た)))))) (PERIOD 。))
火山 の 北西 の 斜面 を 流れ落ち た 火砕流 は 後 に 破壊 の 道 を 残し た 。
Pyroclastic flows descending on the northwestern slopes of the volcano left a path of destruction behind .