( 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 was n'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 .
NEW : The evacuation order has been lifted for Northwood , Iowa , official says . Chemical fire cleared out the Iowa town . Score: 6 Four people have complained of breathing problems .