More than 1,300 Californians have died in the line of duty, serving as firefighters.

Their names are etched on the California Firefighters Memorial, in Sacramento's Capitol Park and this weekend, that monument is gaining 31 more names.

Every year, the California Fire Foundation, which erected the memorial 15 years ago, adds names to the brushed limestone wall.

Carroll Wills, communications director for California Professional Firefighters, said most of the names in any given year are those of men and women who have fallen in the line of duty in the previous 18 months.

Among the fallen going onto the wall this year are four Central Valley firefighters: Sacramento Airport FD firefighter Timothy Anderson, Marysville firefighter Gerald Hartman, CAL FIRE firefighter Darwin Vargas of Turlock and U.S. Forest Service firefighter Michael Hallenbeck from the Tahoe Unit, who died fighting a wildfire near Echo Summit in 2015.

Regularly, however, there are names from decades past.

Since the monument is only 15 years old, Wills said, departments across the state are diving deep into their histories and finding the names of men and women who died in the line of duty, whose names are not yet on the wall.

David Terry is one of those historians. He's an an engineer with Humboldt Bay Fire in Eureka, and he's in Sacramento this weekend for Saturday's memorial service.

ABC10 spoke with him Friday evening, at a candlelight walk from the Capitol's North Steps to the nearby memorial.

"We're going to be adding five of our brothers to the wall that are long overdue, (their deaths) spanning from 1934 all the way up to 1964," said Terry. "This is our opportunity to go back and make sure that they have a lasting name to having given the ultimate sacrifice."

He said he'd heard incomplete stories in his department about fallen firefighters, and he wanted to bring those men's stories to light and add their names to the wall.

In his meticulous research, he learned about 23-year-old Leonard Winslow, a young volunteer firefighter and electrician with the city of Eureka, who died en route to a fire when a vehicle hit the firetruck in which he was riding. The year was 1934.

He also learned of George "Pudgy" Davis, a Eureka Fire Department captain, who died in 1947 after suffering a series of paralytic strokes, which were brought on by a leg amputation he needed due to an injury he sustained in the line of duty.

Raymond Somma died in 1961. A 38-year veteran of the Eureka Fire Department, he was described as “one of the best and most fearless men in his department.” He went home sick in April 1961 due to a heart condition that would ultimately, later that year, take his life.

1964 claimed two men from the Eureka Fire Department. Robert McGillivray died from cardiac arrest. At the time, he was the department's most senior member.

Lt. Adolph Oss died after suffering multiple heart attacks while on shift.

Oss' daughter Edythe Olsen was just 23 at the time.

She got the call earlier this year from David Terry that he'd found her father's story and wanted to add his name to the California Firefighters Memorial.

"Finding living relatives...that was the challenging part," said Terry.

He found them spread all over the country.

Olsen, however, now lives in Cameron Park in El Dorado County and attended Friday's candlelight walk to the memorial.

"I wish I would've bought stock in Kleenex. I've cried from the time David first called me," she said, smiling as Terry put his arm around her shoulder. "It's been very bittersweet. It's brought back a lot of memories...It's a memory of a wonderful man, who gave me a great gift even though I lost him when I was 23. He taught me a lot, and he continues to do so. He's in my heart always."

She said she wanted people to know, "my father loved his job."

"These guys laid down their lives," Terry said. "They kissed and hugged their families goodbye and that was the last they saw of them, and they deserve to be on that wall."

The public memorial ceremony is at 11:30 a.m. in Capitol Park. It will also be live-streamed online. The memorial's program is available online HERE. The list of 31 names going on the memorial wall is HERE.

Memorial information - and a link to the live stream - is HERE.