Crosses representing homicide victims sit in a vacant lot in the West Englewood neighborhood on the South Side of Chicago (Tannen Maury/EPA)

Last month, hundreds of people marched through Chicago holding at least 762 wooden crosses, each representing one of the city’s 762 homicide victims that year.

As 2016 closed on Chicago, they marched down Michigan Avenue, the city’s main thoroughfare, holding the four-foot-tall crosses high. Written on the crossbeam of each was the name and age of the deceased and a number, showing the order in which they fell.

“Madison Watson, 4 years old, No. 456,” read one, according to The Chicago Tribune.

“Donald Carter Brunson, 28 years old, No. 522,” read another.

Now, those crosses rest in a lot in the Englewood neighborhood on Chicago’s South Side. The lot is a striking sight, the physical manifestations of lost lives spreading out almost endlessly before one’s eyes.

Their creator is carpenter Greg Zanis. Since the new year began, he has made at least 40 more of the crosses. And that’s on top of all the others he constructs.

Zanis’s woodworking ministry began about two decades ago. A 6-year-old girl was murdered in his hometown of Aurora, Ill. Her mourning mother visited her local carpenter, who happened to be Zanis, and asked him to build a cross to commemorate her daughter’s short life. She could pay $20.

“I wouldn’t take the $20, but I came back in an hour with the cross,” Zanis told The Washington Post in a phone interview.

Since then, in many ways, marking death has been Zanis’s life’s work.

After his first cross for the Aurora girl, word of his good deed slowly seeped through the neighborhood, and those who lost loved ones began requesting the crosses. He made 13 more, all free of charge. Then he made one for his own use. His 71-year-old father-in-law was shot and killed. “They were like father and son. They were best friends,” his wife, Susan, told The Post in 1999.

“I found him dead in a pool of blood at the bottom of the stairs,” Zanis said. “Within a week I built 14 crosses, and one for me.”

“It just blossomed into a beauty ministry where I’d [bring them] to different states,” he said. At this point, he has built at least 16,000 crosses.

“Every year, I put up around 1,000,” he said. “I’ve got 16,000 up right now. I personally put them in place. I write the names on them.”

Greg Zanis, left, of Aurora, Ill., prays with Aurora, Colo., Mayor Steve Hogan at the 12 crosses Zanis made for a makeshift memorial to the victims of the mass shooting at the Century 16 movie theater in 2012. (Chip Somodevilla/Getty)

Added Zanis, “I’d been able to do this on the weekends, but now that I’m retired I can do it whenever I want.”

Driven by his deep faith — “I’m pushing Christ, and that’s pushing hope” — the born-again Christian performed his duty quietly, driving “a million miles” around the country, all 50 states, placing crosses where men and women once stood.

The general public might have seen his crosses but never known of their creator — and Zanis was fine with that.

Then in 1999 Eric Harris and Dylan Klebold took several firearms to Columbine High School in Colorado and killed 12 fellow students and one teacher. Days later, Zanis drove to the school.

“I put up 15 crosses. Two for the gunmen,” he said. “They had mothers and sisters and brothers who were grieving too.”

He added, “That became a hot topic.”

Suddenly, Zanis was known to the nation as newspapers profiled him, noting that an angry father of a slain Columbine student had torn down the cross remembering the gunmen.

“I’m not exactly sure what this commitment is that I’ve started,” he told The Post at the time. “But I’ve started it.”

Eighteen years later, he hasn’t slowed down. After June’s mass shooting at the Pulse nightclub in Orlando, he showed up with 49 crosses in tow.

He doesn’t only build them for national tragedies, but for personal ones as well.

“My phone’s been ringing since New Year’s Day,” he said. “Every 10 or 20 minutes, straight through.”

Most of those calls are requests for a cross. Local lumber yards have donated some wood, other pieces he gets from Craigslist. He strips doors and old fences and thrown-out furniture for usable wood. And Zanis has the time. So he makes them.

Some calls are simply former “clients,” for lack of a better word, expressing gratitude. One man recently arrived at his doorstep with a cross Zanis had constructed 19 years ago for the man’s lost son.

“I get a huge amount of satisfaction from it,” Zanis said.

His message, he said, is this: “It’s ‘Greg Zanis loves you. Somebody loves you. Somebody cares.’ And a lot of times that equates to other people signing these crosses and leaving messages,” he said. “The dead person doesn’t see the cross. This is for you.”