If a room is on fire and none of connnected rooms have dwellers, you can just wait until it ends. Storage rooms and Living Quarters don't need dwellers, so I put all
Storage Room - Fallout Shelter Wiki Guide - IGN
How To Improve Your Fallout Shelter SPECIAL Stats
Assign X Dwellers to the right room" And You: foshelter
Fallout Shelter: Tips, tricks, and strategy to keep your dwellers free of radiation | iMore