On February 19 , 2006 , an explosion occurred in a coal mine in San Juan de Sabinas , Coahuila , that is owned by Grupo México . It was reported that mine workers had gone on strike against Grupo México at least 14 times , " not only for salary increases … but because of its constant refusal to review security and health measures . " Grupo México said that they , in conjunction with the mining union , signed a certificate on February 7 , 2006 declaring the mine safe
explosion
Pasta de Conchos mine disaster
Grupo México