A chemical leak at US Foods in Alcoa prompted city officials to order a shelter-in-place yesterday night, as concerns about an ammonia spill were raised. Residents and businesses were alerted around 8:10 p.m. to the potential hazard, as first responders from the City of Alcoa Fire Department arrived at the scene with heavy equipment and additional personnel. “At no time did we get any readings outside of the plant facilities and at no time was the public in danger,” Alcoa Fire Chief Roger Robinson reported in an interview with WVLT News.