fateful

having momentous consequences; of decisive importance; "that fateful meeting of the U.N. when...it declared war on North Korea"- Saturday Rev; "the fatal day of the election finally arrived"

मेरा मतलब यह विनाशकारी हो सकता है, यह अन्दर महसूस हो सकता है,

politically-motivated gregariousness and poor time organisation proved fateful.