@abcnews: Some residents east of Atlanta were evacuated while others were told to shelter in place to avoid contact with a chemical plume after a fire at a chemical plant. Video shows gray smoke billowing into the sky. Rockdale County Fire Chief Marian McDaniel told reporters that a sprinkler head malfunctioned around 5 a.m. Sunday at the BioLab plant in Conyers. That caused water to mix with a water-reactive chemical, which produced a plume of chemicals. The chief said she wasn't sure what chemicals were included. A small roof fire was initially contained, but reignited Sunday afternoon, Sheriff Eric Levett said.