Update: A memorial for Clark will be held at Morgan's Pier (the old Rock Lobster) on Sunday, June 7 at 1 p.m.

If you worked at or patronized a nightclub in Center City Philadelphia during the last 25 years, chances are good that Clark Maloney had a role in your experience.

The hospitality veteran - who managed or consulted for a staggering array of establishments, most recently the club 1925 near Rittenhouse Square - died unexpectedly May 16, less than a week after receiving a kidney transplant. He had been undergoing dialysis for eight years, his brother, Gregg, said this week.

He was 53.

He oversaw the Delaware Avenue venue Rock Lobster from 1996 to 2002 and its successor, Octo; had an ownership interest in Milkbar, Eighth Street Lounge, and Club 111; and more recently ran Whisper near Rittenhouse Square. He worked for the Black Banana, Egypt, Revival, Shampoo, Gasoline, Smoke, Maui, Xero, G Lounge, Fluid, Isla Verde, Paradise Alley, 2nd Story, Transit, The Bank, Elan, Katmandu, Silk City, and dozens of others.

His skills were rare and varied. He could discuss the bottom line with investors and manage the hundreds of details essential to a club just as easily as he could mentor employees and make them laugh - after keeping them at work until the place was cleaned to his satisfaction. A bear of a man, he doted on his niece Ava and nephew Devin.

In a high-turnover, ephemeral business, he made it a point of keeping friends for life.

"We were so close - I was his shadow," Gregg Maloney said of his only sibling. "We were like twins, even though he was 10 years older. You couldn't tell us apart." The Maloneys grew up in Harrisburg, the children of Lois Anne Maloney, who survives, and John W. Maloney III, a school principal who died in 2013.

Though Clark moved to Philadelphia after his graduation from Lehigh University, he and Gregg spoke almost daily.

Dozens of reminiscences now fill Clark's Facebook page, most expressing shock at his passing.

"He had an invincible presence," said Toni Morelli Shepherd, now director of admissions for the Restaurant School at Walnut Hill College. She recalled that during her 2009 interview for a bartender's job at Octo, Clark worried her. "He didn't say much," she said. "But he was taking it all in."

Shepherd described Clark as a natural teacher and leader, imparting lessons even when he didn't have to. "I remember one morning when he dropped by. The house was a disaster, and the kids were running around, and I offered him something to eat. He told me to sit down and said, 'I didn't come here to eat. I came to see you.'"

Later, she said, he drew a triangle on a sheet of paper and gave it to her. On one side, he wrote, "Happy kids." On a second side, he wrote, "Your sanity." On the third, he wrote, "Clean house."

He told Shepherd: "You can only have two."

In 1993 or 1994, while bartending and managing at Xero, then in Queen Village, Clark struck up a friendship with Anthony Covington, a customer who was a diamond salesman at Robbins 8th and Walnut. "He treated me like his little brother," said Covington, noting that as two single African American men moving in a mostly white downtown professional scene, they felt a kinship. They became roommates in Queen Village, sharing a house on Passyunk Avenue near Catharine Street. Clark had lived in the Queen Village/Bella Vista area for many years.

"He was the most generous, kindest, most thoughtful guy I have ever met," said Covington, who said his friend took the time to help write the business plan for his office-furniture company.

Though ill for a decade, Covington said Clark kept it quiet. "He never complained. He wanted to worry about other people. He didn't want people to worry about him."

Kellyann Beene, who co-owns the Urban Saloon and met Clark when he hired her at Rock Lobster, said: "His name could be interchanged with 'love' in the Corinthians. He wasn't just popular. He was the real deal. He was always pushing to you to improve in life. He always said, 'You have to be a beast.'"

She also commended Clark for setting a professional tone. "He ran a clean, safe environment," she said. "Between him and Marty [Keenan, the owner], it was a family."

A viewing will begin at 10 a.m. Tuesday, May 26 at Wesley AME Zion Church, at Fifth and Camp Streets in Harrisburg. Gregg Maloney said a small graveside service would follow.

Friends are arranging a Philadelphia memorial.