"Senseless tragedy," said Homicide Capt. John Ryan. "Senseless violence."
The attackers remained at large Friday afternoon. Ryan declined to discuss what leads police were pursuing.
"He was the neighbor and friend I wish everyone was fortunate enough to have," said Brad Griffith, 40, a longtime friend who lives about a block away. "And I'm going to miss him."
Chief Inspector Scott Small said Grandzol "was shot from point-blank range."
Responding officers took Grandzol to Hahnemann University Hospital, where he died at 9:42 p.m.
According to a 2012 Daily News story, Grandzol had lived in the Spring Garden/Francisville neighborhood for more than a decade and was a board member of the Francisville Neighborhood Development Corp.
He was a supporter of development in the neighborhood, in which tensions over gentrification linger. Neighbors said he was friends with area residents new and old.
Penelope Giles, founder and CEO of the Francisville organization, struggled with her thoughts when speaking of her former board member Friday.
"I've been on the phone with friends and other board members, and right now I have no words. I can't say anything. I'm devastated," said Giles. Grandzol became a member of the board when his family moved to Francisville and remained with the organization until they moved, she said.
Grandzol, a graduate of St. Joseph's University, was executive director of Special Counsel's Philadelphia office. Special Counsel describes itself as "the leading provider of contract and direct-hire attorneys and paralegals in the area."
On his Twitter account, Grandzol described himself as an "avid ice hockey defenseman, chef and creator of fine household items." Many of the posts contain links to photos of his wife and children.
Clarke, whose City Council district includes Grandzol's block, said Grandzol was well-known and well-liked when he interacted with Clarke's office staff — a point person for initiatives in the neighborhood, including an effort to repurpose one of the few abandoned houses near the block.
"He was kind of like the go-to guy in that community," Clarke said.
Clarke lamented that Grandzol's life was cut short, and said city officials would continue to pursue solutions to violence in a city that typically records nearly 300 murders and more than 1,000 shootings a year. As of Thursday night, according to police statistics, the city had recorded 210 murders in 2017 — a 6 percent increase over the same point last year.
"We can't just act like it's OK," Clarke said.
Ye Wan, who lives across the street from Grandzol's house, said he was a "fabulous person" whom she saw almost every morning walking his daughter and dog on the block. "He was always just so happy," she said.
Nate Proulx said Grandzol introduced him to everyone on the block when Proulx and his young family, including his two kids, moved in a few months ago. Neighbors gathered almost every night on the block to hang out and watch their kids play, Proulx said, and Grandzol loved being in the middle of it all.
"He loved it here," Proulx said.
A Facebook page has been set up in his memory, with dozens of commenters wishing his family well.
Staff writers Joseph A. Gambardello and Mensah M. Dean contributed to this article.