The storm killed four people and caused $11 billion in damage, with the greatest destruction in a wide strip of eastern Iowa, where winds exceeded 100 mph. In cities such as Cedar Rapids, the wind toppled thousands of trees but the damage to a corn crop only weeks from harvest was especially stunning.

WYOMING, Iowa — Taking a late-summer country drive in the Midwest means venturing into the corn zone, snaking between 12-foot-tall green, leafy walls that seem to block out nearly everything other than the sun and an occasional water tower.