Sentence:  The very thing the 16 skiers and snowboarders had sought — fresh, soft snow — instantly became the <WSD>enemy</WSD>. Somewhere above, a pristine meadow cracked in the shape of a lightning bolt, slicing a slab nearly 200 feet across and 3 feet deep. Gravity did the rest. 
Meaning of the word marked with <WSD> tags:  Something harmful or threatening to another