The answer to you question is Sentence 2. Sentence 2 says "This was around the time that the United states men's ice hockey team shocked the world by winning the gold medal in the winter Olympics in Lake placid."
The reason sent. 2 does not belong is because the whole paragraph is talking about turning a piece of land into a arboretum while sent 2 is talking about a hockey game that was surprisingly won.
Hope this helps! :)