ERIE -- Investigators say they still don't know what caused a massive pipeline fire this week in western Illinois.
Monday's rupture and fire in Erie created a 15-foot-deep crater in a cornfield and sent rolling flames hundreds of feet into the air. The fire could be seen for miles.
WNIJ-FM reports (http://bit.ly/13q1s3F ) the investigation is being led by the U.S. Pipeline and Hazardous Materials Safety Administration. A spokesman tells the station that an investigation typically takes about 20 months. Crews will send a portion of the ruptured pipe to a lab to be tested.
The pipeline was carrying a mixture of ethane and propane from Iowa City, Iowa, to a petrochemical plant in Morris, Ill., about 62 miles southwest of Chicago.
No one was hurt.