Board Thread:Speculation House/@comment-27027823-20150928204654/@comment-73.149.223.52-20150929005115

I don't think the grimm in Breach were trapped underground. The bombs were intended to blow holes in the tunnel to the surface so that the grimm could get into the tunnel and thus into the city when the train breached the cities defenses. Also, the beginning of the tunnel where Roman, etc.. had their base was open into the abandoned city, so they could have left through there if they wanted to.