(CNN) -- The federal government has cited a subcontractor for safety violations after a natural gas explosion that flattened a popular restaurant in Kansas City, Missouri, killing one person, officials said Thursday.
The February explosion occurred when an employee of Heartland Midwest LLC, a communications utilities contracting company, hit a 2-inch gas line with an underground boring machine about an hour before an explosion at JJ's Restaurant, according to local and federal authorities. The employee was laying fiber optic cable.
The explosion killed one patron at the restaurant and wounded at least 15 people, including three employees of Heartland Midwest. It also damaged a handful of nearby buildings.
"This explosion was a tragic event that stemmed from errors on behalf of Heartland Midwest," Marcia Drumm, acting regional administrator for the U.S. Department of Labor's Occupational Safety and Health Administration in Kansas City, said in a written statement.
"Companies, such as Heartland Midwest, have a responsibility to train employees about the hazards that exist on work sites. It is heartbreaking that a person was killed and numerous employees were severely injured as a result of these violations."
An attorney for Heartland Midwest rebutted OSHA's findings, saying they were merely claims, not conclusions.
"Heartland Midwest understands that this is simply the initial starting point of a legal process which will force OSHA and its representatives to present evidence to a judge to support claims it feels are weak and ill-defined," attorney Brad Russell said in a written statement e-mailed to CNN.
"Certainly, no one should mistake these citations as a conclusion about the legal responsibility for causing the explosion of February 19, 2013."
OSHA cited Heartland Midwest for two violations, one for failing to provide a safe work environment for its employees and the other for failure to provide its employees with footwear to protect them from electrocution.
The company faces a possible fine of up to $161,000, according to OSHA.
But Russell faulted OSHA's findings, saying it has issued no rules, regulations or published guidelines concerning the proper methods to safely conduct underground drilling.
CNN's Mayra Cuevas contributed to this report.