Sentence:  In a sense , the showdown promised by Mr. Hammarskjold 's sudden and <WSD>tragic</WSD> death has been avoided ; no precedents have been set as yet ; structurally , the U.N. is still fluid , vulnerable to the pressures that its new and enlarged membership are bringing to bear upon it . 
Meaning of the word marked with <WSD> tags:  very sad; especially involving grief or death or destruction