ROMULUS, Mich. (AP) -- Hundreds of people were advised to remain away from their homes Wednesday as a fire at a suburban Detroit chemical plan continued to send smoke over their neighborhoods.
At least 32 people _ including some firefighters _ were treated at hospitals, Oakwood Healthcare System spokesman Tom Worobec said.
Most complained of a burning sensation in their mouths or difficulty breathing. Some firefighters also suffered heat-related illnesses as they fought the fire in humid conditions with temperatures reaching into the 80s.
All but a few of the patients were treated and released by Wednesday afternoon, Worobec said.
Witnesses said they heard several loud explosions shortly before 10 p.m. EDT Tuesday night at the E.Q. Resource Recovery Inc. plant in Romulus, then saw flames and smoke shoot into the sky. The facility recycles chemicals such as airplane deicing fluid and industrial paint solvents.
Mayor Alan R. Lambert said one tank exploded, then set off explosions in others at the plant. Uncertainty about the chemicals involved and the intensity of the fire initially kept firefighters from getting too close to the blaze.
By dawn, however, the fire had died down, and crews moved in to put water and foam on the remaining flames. A small hotspot continued to burn as of Wednesday afternoon, according to a spokesman for the U.S. Environmental Protection Agency.
Eight employees were working at the plant before the explosions, but they evacuated when an emergency horn sounded, and none of them requested medical treatment, company spokesman Dan Gilbert said.
''They really couldn't tell us anything real concrete that would tell us what caused this,'' Gilbert said. ''As soon as the situation stabilizes, we're going to start an investigation.''
Romulus police evacuated homes in a one-half-mile radius, while officials in neighboring Wayne initially cleared out about 1,000 homes in an area under the path of the fire's smoke plume. About 150 homes in Romulus and 750 homes in Wayne remained evacuated Wednesday afternoon.
Many residents took refuge in two schools, where the American Red Cross provided cots and food. Officials said many others were staying with relatives elsewhere.
Wayne City Manager John Zech told evacuees at Wayne Memorial High School that they had the option to return to their homes, but fire officials recommended that they stay away until environmental tests were completed. The EPA hoped to have more concrete test results Wednesday night.
''The situation at the site is still unstable, so we do not have the all-clear sign as of yet,'' Zech said. ''There are some unknowns, and the severity of the unknowns we're not sure of.''
Hazardous materials officials had tested the air quality and found no danger present, Romulus Public Safety Director Chief Charles Kirby said. EPA workers were conducting more tests Wednesday.
Among the lingering concerns were possible dangers from the blanket of ash the fire had deposited on homes, cars and sidewalks in the evacuated area.
''We don't want anybody exposed to anything that would harm them,'' Zech said. ''If the dogs are walking on it, or you are, or your children, then you're going to be tracking it in your house, and we're concerned about that.''
Only a few dozen people remained at Wayne Memorial by Wednesday afternoon. But Imogene Williams, 80, said she wouldn't take any chances by returning home before officials said it was OK.
''If they say it's necessary to stay another night, we'll have to,'' Williams said. ''I just pray to God to protect my home.''
Romulus is located about 25 miles southwest of Detroit and is home to Detroit Metropolitan Airport. Mike Conway, a spokesman for the airport, said flights weren't affected by the fire.
