CHICAGO (CBS) — Greg Zanis has been building wooden crosses to commemorate the tragic loss of lives for more than 20 years.

His crosses were at Columbine High School, the Boston Marathon bombing and, more recently, at the Orlando nightclub shooting.

On Sunday, Zanis, 66, a retired carpenter from Aurora, erected nearly 40 crosses in a grassy lot in Englewood.

Each represents a homicide victim killed in Chicago in 2017, and another will be added for every person who’s killed in the city this year, he said.

If last year is any indication, Zanis will be busy. A total of 780 people were victims of homicide in Chicago in 2016.

He made crosses for all of them, too. They were carried by demonstrators who gathered downtown on Michigan Avenue on New Year’s Eve to march against violence.

On Sunday, several pastors gathered to pray at the site of the newly erected crosses at the the grassy lot near the corner of 56th and Bishop. It sits between two homes, one of which is boarded up.

A woman played the flute as Pastor Dan Haas, of Aurora, read each murder victim’s name and told the story of Cain and Abel.

“We believe that our prayers make a difference,” Haas said. “It’s not just a religious exercise for us,” he said.

A woman who asked not to be named gave him the land, said Zanis, who grew up in Chicago.

Why Englewood? “Englewood is well-known all around the country for violence,” he said.

Each cross takes about 10 minutes to build from lumber that was donated.

Zanis began building crosses after his father-in-law, Bud Stadler, was robbed and murdered in 1996.

“I just have had a loss myself and I know what people are going through, and it’s just so important that somebody reaches out to these families,” he said Sunday.

Family members are encouraged to go to the lot in Englewood and retrieve the cross bearing their loved one’s name, Zanis said.

“I’ll replace it with another one so the count will be complete,” he said.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2017. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)