John Carl Warnecke, the architect who helped design Hawaii's state Capitol and worked closely with the Kennedys on numerous projects, including President John F. Kennedy's grave site at Arlington National Cemetery, has died. He was 91.

The California native died last Saturday from pancreatic cancer at his ranch near Healdsburg, Calif., along the Russian River, his son, Fred, said.

In 1977, just before he began scaling down his practice, Warnecke ran the largest architectural firm in the United States, with offices in San Francisco, Los Angeles, New York, Boston, Washington and Honolulu.

His firm, along with Belt, Lemmon & Lo and Architects Hawaii, designed the state Capitol with its symbolism reflecting the uniqueness of the islands and extensive open space, to convey a sense of open government, according to the state of Hawaii website.

Jahn-Peter Preis of Preis & Associates Architects in Kahaluu recalled working as a designer for Warnecke one summer during the Capitol project.

He said he worked on housing projects in Hawaii Kai and a master plan for West Maui, and his father, architect Alfred Preis, was involved with some of the final design of the Capitol and the master plan for the Capitol District.

He said Warnecke made a “;tremendous”; contribution to Hawaii. “;The state Capitol is a beautiful building. It's an icon in Hawaii. I love the building.”;

Warnecke met Kennedy in the 1960s through a mutual friend and developed a close friendship with the first couple.

The president tapped him to restore Lafayette Square across from the White House in 1962.

“;The Kennedys enjoyed his philosophy,”; said Harold Adams, 71, who worked for Warnecke from 1962 to 1977. “;I think they just got very comfortable with him and had great respect for him and his work.”;

Warnecke was a proponent of contextual architecture, known for bringing a sensitivity to environment and history in his designs.

In Lafayette Square his design preserved historic townhouses and placed new government buildings behind them, Adams said.

At the naval academy in Annapolis, Md., his expansion plan worked within the academy's existing footprint.

And in Hawaii he designed the state Capitol building to blend in with the 19th-century Iolani Palace nearby.

Even the president's grave site with its eternal flame reflected his style.

“;He was very firm that it had to be a very simple design that fit the landscape,”; Adams said.

After the president's death, Warnecke developed a romantic relationship with Jacqueline Kennedy, his son said. “;They remained friends even toward the end of her life,”; he said.

Warnecke was born in Oakland, Calif., on Feb. 24, 1919. He graduated from Stanford University in 1941 and went on to complete a master's degree in architecture at Harvard University the following year.

Fred Warnecke said his father spent much time at his ranch and vineyard in Healdsburg after retirement.

Star-Bulletin reporter Helen Altonn, the Associated Press and The New York Times contributed to this story.