NEW IBERIA, LA --A fire at a plant where chemicals are blended and stored for oilfield operations forced residents to evacuate or hunker down Tuesday night while a grayish-brown column of smoke rose hundreds of feet into the air hours later. Investigators said no one at the Houston-based Multi-Chem Corp. plant in this city in the Cajun country of south Louisiana was injured and all 20 workers at the site were accounted for. Officials weren't certain what kind of chemicals were on fire in the warehouse. Louisiana state police and Iberia Parish emergency management officials said the first blast was reported about 4 p.m., followed by several more explosions. The plant is near the Acadiana Regional Airport, which was shut down as a precaution. "It was a big explosion, I mean a big one," said Odis Lounsberry, who was in his front yard near the plant. He said several smaller blasts followed. Lounsberry, who said he is an inventor by trade, said he got a bad taste in his mouth after feeling drops of a liquid hit him. "It was like a bitter taste, just a foul taste," he said. He said he could hear the rush of the flames burning. A short time later, he got a knock on his door and police told him he had to leave. Firefighters have determined the best thing is to let the fire burn itself out. Mary Celeste Clement, a children's book author, lives about 2 miles away and said she evacuated to Lafayette after she saw smoke pouring from the plant. "I packed my bags and left," she said. "I didn't want to take the chance." Twelve people gathered at an evacuation staging area in New Iberia's City Park and likely would be housed in hotels for the night at the company's expense, said Red Cross volunteer George Gauthier. Initially an evacuation order for a 5-mile radius was ordered, but later it was narrowed to 1 mile. Clement said it was scary. "You could tell it was a major explosion, black, black smoke," she said. Clement said friends in neighboring towns told her they could see the smoke for miles. Outside the evacuation area, life in this Oil Patch town of about 32,000 west of New Orleans went on almost as usual. People were out in the afternoon heat mowing lawns and socializing. Katie Dupuis, a spokeswoman for Multi-Chem, said the fire started where the company stores chemicals in outdoor tanks. Multi-Chem blends a variety of chemicals used in the oilfield industry. She said the company was trying to determine which chemicals were burning and that at least two storage tanks were burning. Dupuis said it was too early to know what caused the explosions and fire. "We know our employees followed proper protocol," she said. The plant is near a primate center where 6,500 animals are housed. University of Louisiana-Lafayette spokeswoman Christine Payton said primates houses closest to the fire were checked and apparently were unharmed. New Iberia was founded in 1779 when Louisiana was under Spanish colonial administration. It is a blue-collar town typical of the state's coastal communities. The region is known for its salt deposits and the Tabasco hot sauce produced at nearby Avery Island.