(S (S (S (NP (BASENP (DT An) (NN explosion)) (PP (IN in) (BASENP (DT a) (NN coal) (NN mine)))) (VP (VBZ has) (VP (VP (VBN killed) (NP (QP (ADVP (IN at) (JJS least)) (NN 80)) (NNS people))) (PP (IN in) (NP (BASENP (DT the) (NN city)) (PP (IN of) (BASENP (NN Donetsk) (COMMA ,) (NNP Ukraine)))))))) (COMMA ,) (SBAR (IN while) (S (BASENP (NN 20) (NNS people)) (VP (VBP are) (VP (VBN reported) (ADJP (JJ missing))))))) (PERIOD .))