Firefighters say an explosion occurred at a chemical plant in Hood County, Texas, CBS Dallas-Fort Worth reports. One person was missing and another was badly injured in the blast. At least four ambulances responded to the scene. Authorities are advising the public to go to the hospital if they came into contact with smoke from the explosion. The incident occurred in the city of Cresson on State Highway 171. No evacuations have been reported in the area. Cresson Mayor Bob Cornett said the liquid chemical plant manufactures products like soap and acid. He said there has been a massive fire department response to the explosion. The cause of the explosion is being investigated.