SEWARD, Ill. (AP) _ An ammonia leak at an agriculture plant sent a noxious white cloud wafting over this small northern Illinois town, sickening at least 10 people and forcing residents to evacuate, authorities said.
Sgt. Aaron Booker of the Winnebago County sheriff's department said early Tuesday that the leak had been stopped.
A mandatory evacuation had been issued for the town's less than 1,000 residents, who were told to go to one of two high schools in the nearby villages of Pecatonica and Winnebago, both less than 8 miles away, authorities said.
A voluntary evacuation was later issued for those villages. It was not immediately clear how the voluntary evacuations affected those seeking shelter in the high schools, but Booker said fewer than 50 evacuees were at either building late Monday.
Workers were transferring anhydrous ammonia from a Seward Agricultural Supply Inc. storage tank to a tanker truck late Monday when the hose burst open, State Police Sgt. Mark Nytko said. The storage tank holds 9,000 gallons, but it was unclear how much ammonia was in it at the time of the accident, he said.
Ten people, including at least one firefighter, were hospitalized with respiratory problems, a Rockford Memorial Hospital spokesman said. As many as eight patients were expected to be treated and released, and none of the injuries were considered life-threatening, he said.
A strong smell of ammonia was in the air and a white cloud could be seen drifting from the scene, the Rockford Register Star reported on its Web site.
Seward residents were told to leave their homes as a precaution because the chemical drifts along with the wind patterns, Nytko said. Police blocked traffic around the town.
``It's a small town surrounded by farm community,'' he said. ``It's a low-lying area and that's the beauty of that chemical, it likes to sit low.''
Anhydrous ammonia can be extremely toxic and may be fatal if inhaled. The vapors are irritating and corrosive, according to the federal Emergency Response Guidebook.
Seward is about 100 miles northwest of Chicago.