you are likely to find People in/at/on Mall. you are likely to find Bathroom in/at/on Mall. you are likely to find Counter in/at/on Bathroom. 
Reading is related to Necessary. Necessary is a synonym of Fatal. 
People --AtLocation--> Mall <--AtLocation-- Bathroom <--AtLocation-- Counter 
Reading <--RelatedTo--> Necessary <--Synonym--> Fatal 