Famed architect César Pelli has died at the age of 92. Some of his most notable building designs include the Petronas Twin Towers in Kuala Lumpur, Malaysia, the World Financial Center in New York, the Pacific Design Center in West Hollywood, Calif., Salesforce Tower in San Francisco, and the north terminal of Ronald Regan Washington National Airport in Arlington, Va.

Pelli was born in Argentina in 1926 and later moved to the U.S. in 1952. He received a Diploma in Architecture from Universidad Nacional de Tucumán in 1950 and a Master in Architecture from the University of Illinois at Urbana Champaign School of Architecture in 1954. He became a naturalized citizen in 1964.

Named Dean of the Yale School of Architecture in 1977, Pelli opened his own practice in New Haven, Connecticut with partners Diana Balmori and Fred Clarke. The firm, Cesar Pelli & Associates, was renamed Pelli Clarke Pelli Architects in 2005 as Pelli’s son, Rafael Pelli, and Clarke took on increased roles.

The firm announced Pelli’s death in a tweet Sunday: “‘It is with great sadness that we announce the loss of our founder, mentor, and great friend, César. He was a gifted architect and teacher, two callings he effortlessly combined as one. I am profoundly grateful to my great friend and partner.’ – Fred W. Clarke, PCPA”

“It is with great sadness that we announce the loss of our founder, mentor, and great friend, César. He was a gifted architect and teacher, two callings he effortlessly combined as one. I am profoundly grateful to my great friend and partner.” – Fred W. Clarke, PCPA pic.twitter.com/g3UkbjCIyw

— Pelli Clarke Pelli (@PCPArch) July 21, 2019

The American Institute of Architects (AIA) also released a statement.

“César Pelli was a consummate architect, teacher and mentor. Rooted both in the creative legacy of Eero Saarinen and the pragmatic leaders of west coast development, César transformed skylines around the world and influenced the modern city as we know it,” said AIA executive vice president and chief executive officer Robert Ivy. “A master of both the urban scale and the carefully conceived individual detail, he leaves a legacy that stands as tall as the buildings he designed and as rich as the lives of the many architects whose careers were shaped by his generous teaching.”