(IDAHO FALLS) – Safety concerns are halting operations in the Materials and Fuels Complex at the Idaho National Laboratory. Officials say there is no threat to public safety, and that two minor accidents last week prompted a safety review. Authorities say a 3,000 pound piece of steel fell to the ground unexpectedly, and nearly hit an employee. Later a fire broke out on the roof of one of the complex buildings. Managers and employees will undergo safety training today, and if all goes well, operations should be back in full swing later this week.