(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 towns to the south until an all-clear was given Thursday afternoon.
Bright said that the facility where the fire broke out houses chemicals used for crop dusting and that some of those chemicals were believed to contain sulfuric acid. Firefighters decided to let the blaze burn itself out, and the column of smoke it put out wasn't expected to affect neighboring communities, he said.
During the evacuation, buses brought Northwood residents to a community center in Kensett, about six 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 had been staying at the community center early Thursday afternoon, and "everyone is OK." The evacuation orders were lifted by midafternoon, said Lori McNalley, the city clerk in Kensett.
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.
CNN's Bill Kirkos contributed to this report.