Mr. DeSantis grew up in Green Tree, graduating from St. Margaret of Scotland School and Bishop Canevin High School. He learned the flower business from his mother at Green Tree Florist, and opened his own shop in Downtown's Gateway Center. At age 26, he became president of Allied Florists of Western Pennsylvania.
Mr. DeSantis convinced the florists to partner with the Builders Association of Metropolitan Pittsburgh to put on the first home and garden show at the convention center in 1982. And when the 2-year-old show was $98,000 in debt, he offered to buy it.
"They said, 'You can have it,' but he said no. He paid off the debt and bought it," his son said. "He had the foresight to know how successful it could be if the right man was running it."
Mr. DeSantis was also among the early preservation pioneers in the North Side's Allegheny West neighborhood. He bought one crumbling Victorian on Beech Avenue, then sold it to buy the one next door. He stripped woodwork, repaired plaster and painted, turning it into a showpiece on the Old Allegheny Victorian Christmas House Tour.
He also befriended an 11-year-old living in the group home next door whose father had died and whose mother couldn't care for him. His name was Mark.
"He chose me," Mr. Moore said. "By spending time with him, I became a better person."
After two years, Mr. DeSantis told his mother he planned to ask Mark to become his son. She asked him why. "Because I love him and I think I can make his life better," he replied.
Mr. Moore remembers riding his BMX bike through the long hallways of the house, where he now lives with his wife, Kimberly, and sons Shane and Riley. His father moved to an even larger house on Brighton Road known as Holmes Hall. This time, with the home show doing well, he could afford to hire restoration experts to make the house a dazzling final stop on neighborhood house tours.
"It looked like someone closed the door in 1889," his son said. "John had the eye."
Mr. DeSantis channeled his love for architecture into the city's Historic Review Commission and was its chairman for 13 years.
For 14 years, he supported music students at nearby Pittsburgh CAPA by paying them to play jazz at the 10-day home show. The original idea — mine — was to have students perform by a re-creation of The Crawford Grill, a famous jazz club in the Hill District. But it was Mr. DeSantis' idea to pay them like professionals.
Paul Thompson, a bassist and longtime teacher who directs the CAPA House Band, said playing at the home show has become a point of pride for generations of CAPA students.
"Some have become professionals. For others, it was the first and only time they were paid to play," Mr. Thompson said. "He created something really special and magical."
Another magical creation of Mr. DeSantis' is the model railway rooms at Holmes Hall. His world-class collection of standard-gauge toy trains began with a used Lionel set he received as a child. Since standard-gauge trains were no longer being made, he began to buy locomotives, running stock, track and other accessories at garage sales and later auctions and collectors' conventions. In the early 2000s, he outbid rock legend Neil Young for a rare Lionel prototype.
Mr. Desantis' train collection has been featured on the "Today" show and became a popular attraction during Allegheny West's annual Christmas house tour. It also brought him many hours of joy as he shared it with his beloved grandsons, who believe "Pap-Pap" wanted his collection to become part of a museum when he was gone.
They treasure memories of a grandfather who picked up sticks in nearby Allegheny Commons to use in sword fights. Mr. Moore said he did the same for him and his brother, David Augustine, who died in a motorcycle accident in Los Angeles in 2009. Mr. DeSantis also found him at the group home.
"He was somebody who would pull you up, show you the light and keep you on his shoulders," Mr. Moore said. "He changed my life, made me into the man that I am today."
Other survivors are his brother, Joe DeSantis, sister, Elaine Ellenberger, and step-brother, Joseph Tancraitor.
Visitation is scheduled for 5-8 p.m. Friday and 1-4 p.m. and 6-8 p.m. Saturday at William Slater Funeral Service (412-563-2800), 1650 Greentree Road, Scott. The funeral is at 11 a.m. Monday at Calvary United Methodist Church, 971 Beech Ave., North Side. Interment at Allegheny Cemetery will be private. www.slaterfuneral.com