Bernard Cywinski, who died Wednesday at 70, was more than just the architect behind Philadelphia's rebuilt Independence Mall, its refined new Liberty Bell Pavilion, and its first Apple store. He also served as the genial paterfamilias of the city's architectural community.

Mr. Cywinski never taught at any of the city's design schools, unlike many of his peers, yet became a friend and mentor to a cross section of architects young and old during his 30 years at Bohlin Cywinski Jackson, one of the city's most respected firms. He loved to gather people around a table, be it for a BCJ design meeting or a leisurely meal. Often the former morphed into the latter.

Mr. Cywinski, who had battled cancer for more than a decade, belonged to the last generation of architects taught to express ideas by drawing. He sketched as easily as he spoke and was admired for his evocative illustrations. Because he never got the hang of drawing on a computer, he would sit with young designers and "essentially do backseat driving," recalled Kelly Vresilovic, who sat next to him at BCJ's South Broad Street office.

The irony is that the firm, which has offices in five cities, is best known today for creating the prototype for the Apple stores, including the glass cube on New York's Fifth Avenue, and for designing a massive Seattle home for Microsoft chief Bill Gates.

Mr. Cywinski didn't participate much in those projects, preferring to keep closer to Philadelphia. He got his moment in the sun, instead, when he was hired in the late 1990s to help reconfigure Independence Mall and design a modern shelter for the Liberty Bell. He always maintained, however, that those projects weren't his work alone because "buildings are made by many hands."

To look at Mr. Cywinski, who grew up in Trenton, you would never guess he could be such a warm, gregarious personality. A bear of a man, with a corona of white whiskers, he was sometimes mistaken for C. Everett Koop, the somber former U.S. surgeon general.

In reality, said Frank Grauman, his partner at BCJ's Philadelphia office, Mr. Cywinski came across more like the hairy beasts in Maurice Sendak's Where the Wild Things Are. Like those monsters, he would make a formidable first impression, only to quickly reveal himself as a big softy.

At the same time, Grauman said, Mr. Cywinski could be very persuasive, once talking a university president into increasing his project budget from $6 million to $26 million. As Grauman recalled, the president began warning his advisers, "Don't look him in the eye or he'll mesmerize you."

Mr. Cywinski's warmth was evident in his work.

Unlike many architects, he fretted about how his buildings would be experienced by the people who used them. During the design of the Liberty Bell Pavilion, he made numerous sketches exploring how people would move through the space to reach the bell, at the far end of the long building.

When it became clear after 9/11 that he would have to fortify the glass vestibule where the bell is displayed, he fought to keep the new security measures from destroying the building's intended lightness. He came up with the idea of shielding the revered relic within parentheses of smooth white marble. The two curving screen walls serve not only to protect the bell, but also to help reduce the scale of the enclosure, making it feel almost cozy and creating what Mr. Cywinski called a "contemplative space."

Mr. Cywinski not only drew better than most architects but also spoke more poetically. He could rhapsodize at length about the way two materials came together to form a joint. When he persuaded a developer to let him include a balcony in the recent renovation of KYW's original Walnut Street building, he described it as "an element of humanity you don't always see on a commercial building," and added, "It makes the building participate with the street."

Mr. Cywinski was probably less well-known than his partner Peter Bohlin, who won the gold medal last year from the American Institute of Architects. The two men joined forces in 1979, when they merged their firms in a kind of arranged marriage.

Bohlin, then based in Wilkes-Barre, said they had complemented each other perfectly. They were drawn together by their love of sketching, although Mr. Cywinski preferred a mechanical pencil and Bohlin insisted on a traditional wooden one. As their firm grew, Bohlin became a nomad, constantly on the road, while Mr. Cywinski remained something of a homebody. In 1994, their collaboration was honored when the AIA awarded them its annual Firm Award.

Mr. Cywinski, Bohlin said, was a "great, indomitable spirit" who didn't allow his long illness to interfere with his work or interest in good food and art. In the last few years, he even took up watercolors.

He traveled with fellow architect Richard Conway Meyer to Greece and Italy to take classes. In Italy, Meyer recalled, Mr. Cywinski would lead the entire group to a nearby trattoria for evenings of eating, drinking, and singing. "Bernie made friends with the entire staff," he added.

Mr. Cywinski, who is survived by his wife, Nancy, continued working and sketching until illness forced him into a hospital, drawing a concept for a series of sculptural light poles that are intended to be erected along North Broad Street. He hoped that the glowing light masts would help brand that part of the Avenue of the Arts. He died the day that the prototypes were tested. By all accounts, they looked exactly the way he had drawn them.