Accidental? Bad farming?
No way. It's slick terrorism.
Not as spectacular as the WTC, but much more effective.
Think about it. And the perpetrators?
You've heard of Montezuma's Revenge? If you visit Mexico you're warned not to drink the water or eat raw vegetables. Has Montezuma's Revenge traveled North? The ultimate undocumented immigrant?
Can Homeland Security stop it? Or even identify it? No way. It doesn't enter through airport security. It doesn't even wear shoes necessarily. It doesn't need special training. It doesn't need military-strength biologicals. All it needs is shit.
What's the solution? Depends on who is in the White House probably, but here are some options:
Military: Nuke Mexico and California
Diplomatic: Annex the rest of Mexico and declare martial law in California
Humanitarian: Distribute leftover FEMA trailers with indoor plumbing to farmworkers in California and the Southwest.
Legal: Arrest all Latinos and airlift them to Cuba (kill two problems in one fell swoop).
Economic (business): Export all vegetables to Iraq (see above).
All of the above