(CNN) -- Authorities evacuated a small town in northern Iowa and waited out a fire at an agricultural chemical company Thursday after warning that the blaze involved sulfuric acid.
At least four people complained of breathing problems as a plume of smoke rose over the town of Northwood, near the Minnesota state line, said Sgt. Scott Bright, a spokesman for the Iowa Highway Patrol. Officials in Worth County ordered Northwood's roughly 2,000 residents to leave town, sending them to a community center and churches in towns to the south.
"This is a dangerous situation," according to an emergency message from the Worth County Emergency Management agency.
Buses were bringing Northwood residents to the community center in Kensett, about 6 miles down U.S. Highway 65, but the facility was "by no means overwhelmed," said Don Preston, pastor of Bethel United Methodist Church in nearby Manly.
"The facility is sort of breathing people in and out," Preston said. "They get off the buses, and a lot of people, especially the longtime residents, have family and friends nearby, and they come and pick them up."
Northwood City Clerk Amber Julseth said that about 230 people were staying at the community center early Thursday afternoon, and "everyone is OK."
"The flames are down, but officials want to make sure there is no concern with fumes," Julseth said. "We're crossing our fingers that we can go back today."
Bright said that the facility where the fire broke out houses chemicals used for crop dusting and that some of those chemicals are believed to contain sulfuric acid. Firefighters are letting the blaze burn itself out, and the column of smoke isn't expected to affect neighboring communities, he said.
An April fire at a fertilizer company in West, Texas, killed 15 people -- mostly firefighters and paramedics -- when a stock of volatile ammonium nitrate detonated. The blast showed up on seismographs and flattened much of the small town south of Dallas.