Two trains collided in western Wisconsin on Saturday, sending one person to the hospital, authorities said.

Sawyer County Sheriff’s Office deputies responded to a report that two southbound Canadian National trains had collided in a remote area in Wiergor Township. Four train workers received medical treatment at the scene, and one was taken to Lakeview Medical Center in Rice Lake with noncritical injuries.

The crash was the result of one train rear-ending the other train. The first locomotive caught fire and derailed, according to the Sheriff’s Office. The fire was quickly contained.

The trains didn’t contain any hazardous materials, authorities said. Railroad personnel were at the scene early Saturday evening working on cleanup.

The cause of the crash remains under investigation.