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

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 (88.51 kilometers) west 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.