some corn farmers who have filed crop insurance claims are already chopping up their crop for livestock sileage. farmers were expected to harvest close to 15 billion bushels of corn this fall, but the government recently cut that estimate to less than 11 billion bushels. if the drought continues, getting that grain to foreign markets could be tough. low water levels on the mississippi river have forced the u.s. coast guard to put navigation restrictions on some portions of the lower mississippi. diane eastabrook, "n.b.r.," chicago. >> tom: by now, you've probably heard of the fiscal cliff, the spending cuts and tax hikes that go into effect this january if there is no action by congress. while economists say the cliff would solve our national debt problems over the next decade, it might also throw us into a recession. all this week, we're taking a close look at the fiscal cliff and what's at stake. tonight, sylvia hall tackles the defense budget, which faces $500 billion in cuts, and what's at risk for the nation's defense industry. >> reporter: in the early 20th century, johnstown, pennsylvani