Election officials in Georgia’s third most populous county announced Monday that they are shipping hundreds of ballots overnight to voters who requested an absentee ballot but never received it because of a clerical error.

Officials in Cobb County, a fast-growing suburb of metropolitan Atlanta, said on Friday that they failed to mail more than 1,000 requested absentee ballots because the election worker in charge of the machine used to package and mail absentee ballots improperly used a flash drive that records which requested ballots have been sent to voters.

Since the error was discovered, many of those voters have received an absentee ballot or have opted to vote by another method, according to county officials. The rest will have a ballot overnighted to them.

The American Civil Liberties Union and Southern Poverty Law Center filed a lawsuit on behalf of Cobb residents over the weekend. As part of a settlement reached Monday, the county said it will accept any ballots from affected voters by Nov. 14 as long as they are mailed by Election Day.

Cobb County Superior Court Judge Kellie S. Hill signed a consent order on Monday evening after deliberating with the county and civil rights organizations.

The Georgia secretary of state’s office said it has opened an investigation into the incident, calling the failure to mail more than 1,000 ballots “unacceptable.”

Janine Eveler, Cobb County’s election director, apologized for the error during a Monday afternoon news conference.

“We’re so sorry to these voters,” Eveler said. “We’re sick about it, the employee who is responsible is sick about it. She’s in tears all the time. We’re very upset, this has never happened to us, and we just want to make it right.”

Daniel White, an attorney for the county, added: “We want voters to be able to choose how they want to vote. We wanted to make it as convenient as possible. This was just a purely clerical error that an engineer is sick about, and the staff sick about it.”

Eveler said the county has faced high turnover in its election office, and 38 percent of election workers are new to their roles this year. The county lost several employees because they were under “too much pressure, and their own lives were suffering with the extra workload,” Eveler said. Ahead of the election, she said many staffers are working more than 80 hours a week.

“Though that is no excuse for such a critical error,” Eveler said.

Lawyers for the ACLU said they will work to ensure the order is fully implemented but cautioned that the specific incident didn’t account for the full scope of issues with absentee ballots in Georgia this year.

“We are happy that today’s ruling grants a specific subset of those voters a chance to cast their ballot. However, we heard from many voters who are not included in the solution provided today. We hope those voters can somehow exercise their right to vote as well, whether by mail or in person,” said Vasu Abhiraman, senior policy counsel for the ACLU.

A new election law approved last year also shortened the window of time during which voters could request an absentee ballot and the county could deliver it, which Eveler said made it “more difficult to get the number of ballots out in the short time that we have.”