Green Hope High School , at 2500 Carpenter-Upchurch Road in Cary, dismissed students at 9:35 a.m. to accommodate evacuees.
Hundreds of residents who were sent to Olive Chapel Elementary School and Turner Creek Elementary School overnight after being ordered to leave their homes were moved to Green Hope High after lunch, and those two shelters were shut down. Officials said they wanted to have a centralized shelter set up that could care for residents for several days, if needed.
The Wake County 911 center has received hundreds of calls regarding the Apex fire. Officials stressed that 911 should be reserved for emergency calls, and residents are urged to direct their non-emergency calls to the Wake County Emergency Operations Center at 919-856-7044 .
Many local schools also were closed Friday, officials said, and no school buses were running in Apex. Salem Elementary School and Salem Middle School were open, but parents had to arrange other transportation.
The fire is also causing changes involving high school football games for some Wake County schools. Some games will be played Friday night while others have been postponed until Monday.
Apex's central business district, including Town Hall, was closed Friday. Radford said anyone in the area without a legitimate reason would be arrested.
Radford warned residents wandering the streets late Thursday and early Friday to get inside, saying that walking in the smoke would endanger people's lives.
"There are all grades of contaminated materials in this smoke and the fire," he said. "If you see this smoke, get away from it."
Thirteen law enforcement officers and one firefighter were treated for respiratory distress at hospitals in Cary and Raleigh and released. Some had chemical burns on their faces, Weatherly said.
About 20 Apex residents complaining of respiratory difficulties went to the emergency rooms at Rex Hospital in Raleigh and WakeMed hospitals in Cary and Raleigh, officials said. They also were treated and released.
Also, 90 residents of Rex Rehabilitation and Nursing Care Center of Apex were brought to WakeMed Cary Hospital as a precautionary measure. About two dozen were later transferred to Rex because their doctors practiced there.
A state Medical Assistance Team set up a decontamination chamber outside the hospital for a brief time overnight in case firefighters, residents or others came in contact with hazardous materials.
Prolonged direct inhalation of chlorine gas can cause sickness or even death, authorities said. Chest pain, vomiting and difficulty breathing are among the symptoms that might be experienced.
Firefighters were unable to approach the blaze for hours after it ignited because of the explosions and hazardous chemicals.
"We want to get in there as quickly as we can, but we're not going to endanger anyone," Radford said early Friday. "Rather than put water or foam on the fire, it's better to let the fire burn itself out so we don't create a large hazardous area on the ground."
Weatherly said early Friday that the fire appeared to have spread to a nearby petroleum farm, igniting four storage tanks. But he said a subsequent review of the site proved that the fire never spread beyond the EQ plant.
A plane tried to fly over the plant early Friday morning to assess the situation but had to return to the airport because of adverse weather.
Authorities had to move their command post four times to get downwind of the explosions and gas plume. The town's 911 center was relocated from the police department downtown to Apex Elementary School.
Overnight flights at Raleigh-Durham International Airport were rerouted to at least 5 miles from downtown Apex to avoid the fire and explosions, officials said.
Authorities initially evacuated about 100 residences in the Briarcliff neighborhood and sealed off the area. Shifting winds moved the chemical plume in different directions throughout the night, forcing further evacuations.