NiSource is investigating a rupture of its Columbia Gulf Transmission LLC pipeline that occurred about 2:05 a.m. EST Thursday on the system's 30-inch diameter Line 200 in Adair County, KY. Shippers were not being impacted, the pipeline said.

Pipeline personnel detected a pressure drop on the line and "operating crews immediately responded to the alert and determined that there was a rupture in the pipeline," the company said.

"We activated our emergency response procedures and took steps to isolate the damaged portion of the pipeline. The flow of gas was stopped to the damaged pipeline shortly thereafter."

The damaged portion of the pipeline was isolated. “At this time there is no impact to commercial operations or shipper nominations on Columbia Gulf and no impact to Columbia Gas,” the pipeline said in a customer notice.

The event caused an explosion that injured two in the town of Knifley, KY, which is about 90 miles south of Louisville. The injured had been released from the hospital as of late Thursday morning, the pipeline said.

Multiple fires broke out in the wooded area and three homes caught fire, according to Adair County Emergency Management Director Greg Thomas, Reuters reported. Two of the homes were said to be destroyed, as were two barns and four cars.

"We know that there has been damage to homes and there are reports of injuries, as well as an evacuation of the surrounding community," the company said. "A critical and immediate priority for our team is to work with local responders to meet the immediate needs of our neighbors."

The company said it would be investigating the cause of the rupture along with authorities.

Columbia Pipeline Group has nearly 1,400 miles of pipeline in Kentucky alone and 15,700 miles of natural gas transmission pipeline in its entire system.