Five cars left the tracks at about 9:30 a.m., Union Pacific spokesman Justin Jacobs said.
No one was injured in the derailment and the cars all stayed upright. Union Pacific’s main line was unaffected, Jacobs said.
Nampa city dispatch confirmed the damage was contained to the rail lines and said no city resources were involved in the response.
It’s not yet clear why the cars derailed, Jacobs said. There was no immediate estimate as of 1:30 p.m. about how long cleanup would take or when the company’s investigation would be finished, though Jacobs noted the incident was relatively minor.
Three of the derailed cars carried automobiles. One held grain, and one was an empty lumber car.