Federal and state officials continue their investigation into Monday’s explosion and fire at a Rubbertown chemical plant.

Two workers were killed and two others in injured when a furnace exploded at the Carbide Industries plant.

The plant makes calcium carbide, which is used to produce acetylene gas and other chemicals.

Two investigators from the U.S. Chemical Safety Board have begun reviewing documents and interviewing employees.

“It’s a little early to determine exactly where we will go with this investigation. In some cases we will do a full investigation. In other cases it might be a more truncated review, and we might issue a safety bulletin,” said board member Mark Griffon.

The Chemical Safety Board does not issue fines or citations. State occupational safety and health inspectors and a federal EPA official are also investigating the incident.

Rick Howlett is host of WFPL's weekly talk show, "In Conversation."