Federal investigators say a utility wasn't marked before a deadly natural gas explosion in Missouri

LEXINGTON, Mo. — A deadly explosion that leveled one Missouri home and damaged two others happened after a subcontractor drilled into an unmarked underground gas main while installing fiber optic cable, the National Transportation Safety Board announced Monday.

One person was killed and two others were injured in the April 9 explosion in the 4,500-person town of Lexington, Missouri, which is about 55 miles (89 kilometers) east of downtown Kansas City.

Liberty Utilities, a subsidiary of Algonquin Power and Utilities Corporation, sent someone out to mark its lines before the subcontractor began digging, but the uncapped gas main section involved in the accident wasn't identified, the NTSB said in its preliminary report.

A few hours before the explosion, the subcontractor felt their drill strike something and smelled odorized natural gas. The crew supervisor then called 911.

Firefighters and a crew with Liberty Utilities arrived and worked to stop the flow of gas. One business about 15 feet (4.6 meters) from the leak was evacuated. But several other nearby buildings were not evacuated, including the destroyed and damaged homes, which ranged from 80 feet to 160 feet (24 to 49 meters) from the leak, the NTSB said.

The NTSB said it continues to investigate the evacuation procedures and Liberty Utilities’ repair history, record keeping and emergency response. The utility responded in a statement that federal regulations limit what it can disclose about what it described as a “terrible tragedy.”

“We will continue to do our part to help those affected and support broader recovery efforts,” the statement said.