Ten of the derailed cars on the eastbound Canadian Pacific train were carrying ethanol, some of which was leaking into the river, Dubuque Fire Chief Rick Steines told the Dubuque Telegraph Herald. He said it wasn't immediately clear how much.
"The scene is really hard to access right now. It's right along the river at the edge of a valley with very poor access," Steines said in a videotaped interview posted on the newspaper website.
The cars went off the tracks at 11:20 a.m. in a remote uninhabited area about 10 miles north of Dubuque. Steines said no one was being allowed within a half-mile of the burning cars as a precaution but that the nearest farm was outside the safety zone so no residents were evacuated.
The railroad had emergency response equipment designed to handle derailments on the way and a hazardous materials team also was responding.
"They'll have to determine the next step," Steines said.
Iowa Department of Natural Resources spokesman Kevin Baskins said his department sent officers to the scene to assess the environmental impact but they weren't being allowed near the train. He said officials in Davenport, Burlington and Keokuk, which use the Mississippi River as a drinking water source, were notified as a precaution.
Two crew members on the train escaped without injury, railroad spokeswoman Salem Woodrow said.
"CP's emergency protocols were immediately enacted and all safety precautions and measures are being taken as our crews respond to the incident," she said. "At this time our focus is public safety and the environment."