An overnight fire burned down a chemical plant in the US state of Oklahoma, with no injuries reported, authorities said Thursday The blaze broke out on Wednesday night at a Danlin Industries facility on the outskirts of Thomas, a small city about 150 km northwest of Oklahoma City. No one was in the plant when the fire was ignited, so there was no report of injuries, officials said. The fire caused huge explosions and forced the evacuation of several homes nearby. Jamie King, a Thomas resident who lives about 1.5 km from the plant, recalled the scene as \"frightening.\" \"There was thick black smoke. It was so dark and heavy,\" King said. \"It was exploding back to back.\" Federal investigators from the Occupational Safety and Health Administration (OSHA) and inspectors from the state fire marshal\'s office are responding to the incident, an OSHA spokesman said. Warren Manley, Thomas\' emergency management director, said the fire was so fierce that responders were not able to get close to it. \"We didn\'t fight this fire at all. We just let it burn. It was too intense, too dangerous to get close to,\" Manley said. The fire was still smoldering Thursday, but crews had it under control, he said. Manley described the debris as a \"total loss.\" He did not have a damage estimate, but predicted it will be \"in the millions.\" It is still unknown what caused the fire. The family-owned company, which produces chemicals used in oil fields, has offices in seven U.S. states, according to its website. OSHA has no records of prior inspections of the plant, but is investigating the cause of the fire.