People in the northern part of Rockdale County were ordered to evacuate and others were told to shelter in place with windows and doors closed.

A fire in the plant near Atlanta caused water to interact with a chemical that set off the plume. A shelter-in-place order was extended Monday morning.

A small fire on the plant’s roof was initially contained but reignited Sunday afternoon, authorities said. More than 90,000 residents east of Atlanta were told to keep sheltering in place Monday a day after a chemical plant fire sent a massive plume of dark smoke high into the sky that could been seen for miles.