The town used a reverse-911 system to call all residences in the evacuation zone to notify people that they needed to leave. Some residents close to the plant site weren't notified of the evacuation because the plume wasn't moving in their direction, so they weren't in danger, Haraway said.
The eastern half of Apex had been ordered to evacuate by midnight, including residents in the Haddon Hall, Surrey Meadows, Knollwood, Shepherd's Vineyard and Weatherford Green subdivisions. Residents in the Sterling Buckingham subdivison were added to the evacuation Friday morning.
"It was one of the most frightening moments I've ever had," one woman said of hearing the explosions and receiving the evacuation order.
Weatherly declared a state of emergency in Apex at about 12:30 a.m. Friday, and Wake County declared a state of emergency about two hours later for unincorporated areas around Apex.
The declarations will make it easier for the town to apply for federal emergency aid, if needed, officials said.
Weatherly defended the massive evacuation, saying he hoped officials would handle a similar situation the same way in the future.
"Our first priority will always be the health and safety of our citizens," he said. "You can't overshoot (on safety) with something like a chemical leak."
The Raleigh Fire Department Hazardous Response Team arrived at the scene shortly after 10:30 p.m. to aid Apex authorities. Over 300 firefighters from Raleigh, Cary, Holly Springs and other jurisdictions also assisted in the effort.
The state Air Toxics Analytical Support Team was brought to the area early Friday to help monitor the air quality following the chlorine gas leak and fire and develop a plan of action.
Firefighters spent much of the night making sure they had the proper equipment to handle various scenarios. Radford said authorities would rely on air quality experts to determine when it was safe to go back into the area around the EQ plant.
All residents within a one-mile radius of Investment Blvd and Sheffelein Road were initially sent to Olive Chapel Elementary on Olive Chapel Road. Those who weren't evacuated were asked to turn off their air conditioners and stay indoors with doors and windows closed until further notice.
About 250 residents had taken refuge at Olive Chapel Elementary by 4:30 a.m., and authorities opened a second shelter at Turner Creek Elementary. Officials also asked residents to seek temporary residence at hotels elsewhere in Wake County or with relatives.
Local Red Cross volunteers arrived at the shelters early Friday to provide food, water, blankets, cots and other items to evacuees.
"Schools are community centers, and we're here to serve the community," Olive Chapel Elementary Principal Melissa Burns said.
All school activities at Apex Elementary, Apex Middle, Apex High, Baucom Elementary, Lufkin Road Middle, Olive Chapel Elementary and Turner Creek Elementary schools were cancelled Friday, Wake County Schools officials said. St. Mary Magdalene School and several day-care centers also canceled classes.
EQ officials arrived at the scene early Friday and provided an inventory of the materials at the plant. Pesticides, fertilizers and other chemicals were stored inside, Apex officials said.
The Wayne, Mich.-based company also set up a toll-free line at 888-675-1680 to provide assistance to residents impacted by the evacuation.
EQ offers services to a variety of institutions that have hazardous chemicals and other materials that must be disposed of according to state and federal regulations. The facility is federally licensed by the Environmental Protection Agency under the Resource Conservation and Recovery Act.
Cregg Johnson, a truck driver who hauls materials to and from EQ, said he was sleeping in his tractor-trailer cab outside the plant Thursday night when a firefighter pulled him out to evacuate as part of the building was engulfed in flames.
"As we were headed off, barrels started blowing, and it just sounded like thunder," Johnson said. "I saw black smoke in the air and it was going south, and I told the firefighters I was heading north."