For most evacuees, home will continue to be a Red Cross shelter, motel room or the homes of friends or relatives until more wreckage is cleared, officials said.
A 21-car Canadian National-Illinois Central freight train carrying hazardous chemicals derailed Sunday morning while traveling through Tamaroa in southern Illinois, sparking chemical fires and prompting officials to evacuate everyone within three miles of the town of 800 people.
The train was carrying methanol, vinyl chloride, hydrochloric acid and formaldehyde, all of which can be flammable or toxic.
Tests showed the chemicals were dissipating before polluting the air in the area, said Peter Marshall, vice president of the Gulf Division for Canadian National.
He and representatives from the Illinois Environmental Association have said groundwater and soil were unaffected.
Officials said they decided to allow some evacuees to return after removing vinyl chloride from a damaged tanker and cutting the risk of fire.
