The National Mining and Metal Workers Union ( SNTMMSRM ) stated Statement that the trapped miners were approximately below ground , via a mile-long horizontal shaft .

On February 23 , 2006 Grupo México advanced Cause_to_make_progress to a part of the mine shaft where they believed two of the 65 workers were trapped .

However , they found Know nobody , leading Causation them to believe the force of the explosion Attack knocked them through the mine shaft deeper than they had anticipated .