unexplained earthworm die-off plagues Ohio

People across the Tri-State awoke to an unusual sight Thursday -- 

thousands of earthworms lying dead on sidewalks and porches.

With no rain in the last week, it's likely that isn't the culprit.
Acidic soil is also unlikely because the worm deaths were reported over such a large area. 

- thousands of worms turn up dead (video)

- untold thousands of dead worms plague Ohio

- Earthquakes, Earthworms, & Earth changes

- Mass Animal Die-Offs of 2010
- Mass Animal Die-Offs of 2011