Brad Russell, a lawyer for the subcontractor’s company, Heartland Midwest, released a statement late Wednesday expressing sympathy for the victims and saying the company is cooperating with authorities. ‘‘We are reserving any public comment until the completion of a thorough investigation,’’ the statement concluded.
The Missouri Public Service Commission, which oversees utilities, launched an investigation into the blast, dispatching five employees to the site.
Commission Chairman Kevin Gunn said preliminary information indicates that gas pipelines had been properly marked. It could take up to six months before a final report is issued.