Yes, seems like it. An engineer acquaintance who builds subway tunnels says that they put in emergency exits every X feet, so that emergency-exiting people never have to walk more than a certain distance before they have a chance to make it to ground level. And in the case of an emergency, massive ventilation fans kick in (that are otherwise dormant). So, from what he's told me, the costs are less in suppression than in providing safe exit opportunities.