OMAHA, Neb. (AP) — American consumers and nearly every industry will be affected if freight trains grind to a halt next month.

One of the biggest rail unions rejected its deal Monday, joining three others that have failed to approve contracts over concerns about demanding schedules and the lack of paid sick time. That raises the risk of a strike, which could start as soon as Dec. 9 under a deadline that was pushed back Tuesday.

It wouldn't take long for the effects of a rail strike to trickle through the economy. Many businesses only have a few days' worth of raw materials and space for finish...