The woman screamed as the phone rang and rang.

Police officers would later describe what unfolded before her.

In a confrontation on Ferrara Drive, two young men fetched their guns and shot at each other. One ran away as a third shooter fired at him.

Residents of Dorchester Terrace dialed 911. Their calls were recorded, even though some went unanswered.

In the first call, the woman yelled. After 30 seconds of ringing, a dispatcher still had not answered. Six gunshots rang out. Then two more.

“Oh Lord,” the woman shouted. “Oh man.”

One minute and 10 seconds after the caller dialed 911, the line went dead.

The woman was heard in two more calls that evening; one was 47 seconds long, the other 20 seconds. Each time, no one picked up, and she cried as the connection was severed.

Dispatchers at the Charleston County Consolidated 911 Center eventually got the call that night, from a man who said his cousin had been shot and was probably already dead.

Within a minute of being dispatched, police officers found the man lying on the ground but still breathing. With wounds in his chest and back, he died two hours later.

Whether a more prompt answer by a 911 call-taker would have made a difference for 21-year-old DaShawn Zellars is unknown.

While no complaints were submitted about that incident, delays in taking 911 calls have resulted in some of the 366 complaints against the center since it opened in 2009. To people who have complained about the center that averages about 225,000 emergency calls each year, the delays could be critical in saving a life or preventing a crime.

One complaint last week pertained to a dispatcher who failed to send a Mount Pleasant police officer to address a report about possible burglars. It prompted a criminal investigation. The probe had not been completed, which is why the center refused to release the document.

The center’s director, Jim Lake, points to statistics that show a decrease in yearly complaints and an increase in the percentage of calls answered within 10 seconds during the busiest time periods, from 74 percent in 2010 to 87 percent in 2012, slightly below the nationally accepted benchmark of 90 percent. To Lake, the improvement is apparent, but with technology’s help, there’s always room for more.

So far in 2013, only 0.5 percent of all calls took more than 20 seconds to answer — 685 of 137,136 calls this year. That compares to 6.2 percent in 2010, when the center became fully operational.

The cities and town that participate in the call center have found consolidation helpful, Lake said, when it comes to communication between firefighters and police officers from different agencies.

But when a fire rages in an urban neighborhood or when a crash ties up traffic during rush hour, it’s usually impossible to answer every call, Lake said. During peak periods, a staff of seven answers calls county-wide.

“We have 30 911 lines ringing into the center, but there’s a limited number of people you can have answering those calls,” Lake said. “It’s really not fiscally responsible to have all those people standing by, waiting for a shooting.”

Room for more

Over the past four years, nine city dispatch centers in Charleston County have become one. The Isle of Palms and Charleston police will join in early 2014.

Separately, those 11 centers were authorized to employ 159 dispatchers in 2009, when consolidation began.

Not all those dispatchers moved to the county center, leaving 95 to bear the load. Only 10 of Mount Pleasant’s 22 dispatchers, for example, switched to the county when the town signed on in February.

Today the center employs 96 dispatchers and supervisors, and Lake has the authorization to hire more. The trouble, he said, is finding and keeping the right people for the job.

Employees are trained not to get wrapped up in a problem that a caller is experiencing. At the end of their 12-hour shifts, though, the emotions can wear on them.

“Once we succeed in getting them in the chairs,” he said, “we have to keep them there.”

To Folly Beach, which joined the center in 2010 but pulled out the next year, dispatching quality was a deal-breaker.

The dispatchers, Mayor Tim Goodwin said, sometimes didn’t know how to deal with problems unique to the city — a dog loose on the beach, an injured sea turtle. Such a “special-needs” community, the mayor said, wasn’t a good fit for a county center that dealt with big cities’ big-city problems.

As the center works through growing pains, Goodwin wouldn’t rule out re-consolidation. He mentioned a button outside City Hall that residents can press, linking them to a county dispatcher who relays the call to the city’s police.

Last week, when others couldn’t get through on their cellphones, Goodwin pushed the button, promptly spoke with a county dispatcher and reported a “drunken disorderly” person.

“If one phone line is tied up, it’s a direct way to get quicker service,” he said. “We’re still trying to work with the county system.”

Yellow, then red

At least 21 people staff the center throughout the day, but the number of workers answering calls fluctuates.

During the peak period for 911 calls, between noon and 8 p.m., seven call-takers are on duty. That number drops to four during the slowest hours, from midnight to 8 a.m.

Working behind the call-takers are 17 supervisors and dispatchers who communicate more exclusively with police and fire service members.

Even with all hands on deck, handling an influx of calls can be troublesome.

Around 6 p.m. Thursday, when a 3-year-old boy accidentally shot his baby sister in North Charleston, a screen at the 911 center on Palmetto Commerce Parkway lit up. It showed the wait times for incoming calls.

Three call-takers, five dispatchers and two supervisors — 10 of the 24 workers on duty — were busy with that incident alone.

“We can’t plan for that. We can’t staff for that,” Lake said. “It ties up resources.”

On a recent day in the building that the center moved into this year, call-taker Jason Scott looked at one of seven computer monitors in front of him.

When a call rings repeatedly, somebody will know about it, he said. After 10 seconds, the big screen that everyone in the dimly lit room can see turns yellow. After 30 seconds, it turns red.

“That’s when we get an alarm in our headset,” Scott said, “so you can’t avoid it.”

‘A little concerning’

Technology is one way dispatchers can better answer calls, Lake said, and reduce the problems that prompt complaints.

During the past two years, the Charleston County Emergency Medical Service most frequently pointed out problems with how calls were handled, according to a review of complaints. They often entailed a dispatcher failing to notify paramedics about certain details, such as a more precise description of a medical predicament.

The residents who complained often accused dispatchers of being rude — likely a result, Lake said, of the questions that call-takers are required to ask.

Only two residents filed complaints about how long it took for their 911 calls to be answered.

Casey Hudson was one of them.

In April, the Mount Pleasant woman was driving at Ben Sawyer Boulevard and Rifle Range Road when a motorist ran a red light and hit her car.

It was the 30-year-old’s first wreck. She wasn’t hurt, but she trembled with nervousness. She didn’t know what to do, so she dialed 911 and listened to her phone ring for 62 seconds. She ended the call when a police officer pulled up.

She later learned that county call-takers had been busy with other calls, including two about the crash. One call-taker was taking a dinner break.

“If it had been a life-or-death situation, I would have been freaking out,” Hudson said. “But at same time, it’s a little concerning that they didn’t have enough people to filter through all the calls.”

Other callers were more forgiving.

After the July shootout on Ferrara Drive, people called 911 nine times.

Michael Brennan, a nearby resident who had heard the commotion, was one of the first to get through after listening to his phone ring for 53 seconds. He was told that dispatchers had been bombarded with calls about the same shooting.

“That’s a stressful situation for them,” Brennan said. “I understood what they were going through.”

And the county center isn’t alone when it comes to the delays.

When gunshots resounded outside a Meeting Street gas station in mid-July, witnesses were already on the phone with Charleston’s police dispatchers. They will join the consolidated facility Jan. 1.

A dispatcher quickly fielded the first call. But the second rang for 51 seconds, the third for 41 seconds and the fourth for two minutes before someone answered.

The same dispatcher handled each call.

Reach Andrew Knapp at 937-5414 or twitter.com/offlede.