CANTON, Ill. - Authorities say the area around a downtown square is closed as crews assess damage from a natural gas explosion that killed one person and injured several others in the central Illinois community of Canton.

The Fulton County Emergency Services and Disaster Agency says early Thursday that secondary searches found no additional casualties and area businesses will remain closed for the day.

Officials say the explosion Wednesday shattered windows several blocks away and forced the evacuation of residents from nearby apartment buildings.

Authorities said the cause of the explosion hasn't been determined. It took place shortly before 6 p.m. after Ameren Illinois workers arrived about 5:30 p.m. following a report that a contractor had damaged a gas line.

Canton, a city of about 14,000, is about 30 miles southwest of Peoria.