Fail is related to Mark. Mark is related to Chance. Chance is a synonym of Accident. 
Wander is a type of Proceed. Proceed is a type of Happen. Fall is a type of Happen. 
Fail <--RelatedTo--> Mark <--RelatedTo--> Chance <--Synonym--> Accident 
Wander --IsA--> Proceed --IsA--> Happen <--IsA-- Fall 