The last time that WDAS radio personality Patty Jackson saw Robert Mendelsohn was on July 18 at the Dell Music Center.

Ne-Yo and Tamia were performing.

“I was hosting," she told me. "I remember standing on the stage and waving to him.”

Jackson loved his work, especially a candid photo he had taken of her with Patti LaBelle at her street renaming earlier this month. She had no idea that concert would be the last time she would ever see him.

Mr. Mendelsohn, a freelance photographer famous for chronicling Philadelphia’s black social scene, has died at 61. The exact time of death has not been determined.

A friend discovered his body Friday night at a rooming house in Germantown where he lived alone, according to his sister, Judith Mendelsohn Marcus, of Delran, Burlington County. She said the cause of death was heart disease.

The day of the Ne-Yo and Tamia concert, Mendelsohn put up a post on Facebook saying, “I’m still looking for new clients to photograph.” Perhaps inspired by that, a potential client reached out to hire him for a photography job but never heard back.

A friend noticed the client’s attempt to contact Mendelsohn, became concerned and volunteered to go to the rooming house on High Street, where she found the beloved photographer in his room on the second floor.

His last Facebook post was July 19.

Freelance writer Marsha Cooper Stroman said she spoke with Mendelsohn the following day, when the heat index crept toward 110.

“Robert didn’t have an air conditioner just a fan at the rooming house where he resided,” she wrote via Facebook Messenger. “He said he wasn’t feeling that great, that it was too hot ... We argued because he wasn’t allowed to have an air conditioner in his room. I told him I was going to call his landlord and he begged me not to.”

“Robert ended our conversation that morning [saying] that he was running out for water and coming right back into the house,” Stroman wrote.

News of his death came as a shock, particularly to those active in the city’s black social scene.

Even though he was white, over the years he shot almost exclusively for black-owned publications such as the Philadelphia Sunday Sun, the Philadelphia Tribune and the Philadelphia New Observer. I learned of his passing from an officer of the Philadelphia Association of Black Journalists.

“Robert was a longtime friend and strong supporter of PABJ and our mission,” said Manuel McDonnell Smith, the group’s president. “We are grieving and will miss him deeply.”

In 2013, I wrote about him for Black History Month because he was at just about every black society and entertainment event I attended, photographing movers and shakers and celebrities.

“I think he felt so welcomed and he felt at home in your community,” his sister told me. "He was accepted. He felt comfortable. He felt like that was his second family. I could tell because when I had a health crisis last year and he reached out and posted everything [on Facebook]. There must have been 400 people who wished me well. It was amazing.”

Councilwoman Blondell Reynolds Brown said she was contacted by four different staffers on Saturday about the news of his death.

“Robert has been at every single event ... that my office has hosted for the last 19 years and he always traveled on public transportation,” she said. “He was devoted to the media outlets he represented ... He always had a smile.”

And he was everywhere. Mendelsohn was known for loving to eat and appreciating a good buffet.

“There are a million Robert Mendelsohn stories to tell, all of them reflect a kindhearted man with a keen eye for the ‘money shot,’" said Helen Blue, who used to work with him at the Philadelphia New Observer.

“Robert Mendelson was black history point blank period,” said Shani Newton, owner of Dolly’s Boutique & Consignment in West Mount Airy. “He knew more about the history than me ... and I’m black lol”

Funeral arrangements are pending.

As a Facebook friend wrote, “I know he’s Jewish but if we have our way, he’ll be going straight to black people heaven because he knew alllll of us. Loved all of us.”

And we loved him back.