Disaster Response Maps has put together before and after aerial imagery of areas affected by the April 9th tornado in Illinois. Before and After the 2015 Tornadoes in Illinois uses the Esri Story Maps swipe tool to allow you to compare the two sets of imagery side-by-side.
Back in 2011 I created something similar after the tornadoes in Alabama. 2011 Tornado Damage - Before and After uses aerial imagery from the NOAA and from Google Maps to compare before and after imagery of a number of areas hit by the April 2011 tornadoes in Alabama.
Over the years the New York Times has created a couple of interactives which allow you to inspect tornado damage from ground level. In Panoramas of Joplin Before and After the Tornado the Times used Google Map Street Views of Joplin side by side with panoramas taken after the 2011 Joplin tornado hit.
In 2013 the Times repeated the exercise after a tornado hit Moore, Oklahoma. Before and After: 360° Views From Moore. The custom Street Views in the interactive are synced with the Google Maps Street Views. If you pan either Street View both the before & after image moves, enabling you to easily compare the images around the whole 360 degrees.