FAIRFIELD &#8212 State environmental officials are investigating a fish kill on a creek that runs through Fairfield.

The fish kill was reported Friday afternoon. Officials with the Iowa Department of Natural Resources said the incident affected a four-mile stretch of Crow Creek near Fairfield and a tributary.

Officials said the impact of the fish kill was substantial but the number of fish killed was not immediately known.

The investigation was continuing and officials were taking water samples to determine the source of the kill.