in front of them are gone, so you can directly see the path moving right straight through there. reporter: as the community grieves, many are asking why. this is the largest event ever in december in terms of severe weather and tornadoes. reporter: experts are working to understand what fueled these monster storms. this is very unusual. josh durkey is a meteorology professor at the university of kentucky. there is warm air ushering in a lot of moisture in the lower levels of the atmosphere, and the wind sheer set up an environment for storms to tap into that environment and thrive. reporter: the unusual nature of the storms have many wondering if this is a result of climate change. climate change is a very complex discussion. reporter: while durkey can t definitively say whether climate change is a cause of these storms, he says they may be a consequence. temperatures in december 30 degrees above average this time of year.