(S (S (NP (QP (ADVP (IN At) (JJS least)) (NN three)) (BASENP (NN fire) (NNS companies))) (VP (VBD started) (S (VP (VBG battling) (NP (BASENP (DT the) (NN blaze)) (COMMA ,) (SBAR (WHNP (WDT which)) (S (VP (VP (VBD engulfed) (BASENP (DT the) (JJ entire) (NN warehouse))) (COMMA ,) (S (S (VP (VP (VBG sending) (NP (BASENP (DT a) (NN plume)) (PP (IN of) (BASENP (NN smoke))))) (PP (IN into) (BASENP (DT the) (NN air))))) (SBAR (WHNP (WDT which)) (S (VP (MD could) (VP (VB be) (VP (VP (VBN seen) (PP (IN for) (BASENP (JJ several) (NNS miles)))) (COMMA ,) (PP (IN at) (NP (BASENP (NN one) (NN point)) (ADJP (JJ darkening) (BASENP (DT the) (NN sky))))))))))))))))))) (PERIOD .))