Union Pacific says their crews are working to clear several derailed coal cars near Milwaukee as quickly as possible.
Twenty cars of a 145-car train left the tracks in West Allis about 6:20 p.m. Thursday, and some coal was spilled in two spots. No one was hurt, including the two workers on the train.
Some of the derailed cars were on a bridge over Highway 59. Union Pacific spokeswoman Calli Hite says two lanes of the highway were expected to reopen Friday evening.
The cause was under investigation.