New York, New York - Ricardo Scofidio, an architect in New York City whose firm designed some of the city's most iconic structures such as the High Line elevated park in Manhattan, died on Thursday at age 89.

Together with his wife, Elizabeth Diller, Scofidio founded the design firm now called Diller Scofidio + Renfro, known for its conceptual building designs.

Among their most prominent projects is the High Line, a 1.5-mile park and scenic pedestrian route built along a former railway on the west side of Manhattan.

The project, a collaboration with architects James Corner and Piet Oudolf, has become one of New York's signature destinations since its opening in 2009.

Scofidio and Diller – who met when he was her teacher at the Cooper Union School of Architecture – opened their architecture firm in 1979. They married in 1989.

Other major projects designed by the firm include Alice Tully Hall at New York's Lincoln Center, The Broad art museum in downtown Los Angeles, and Zaryadye Park, a landscape urban park next to Moscow's Red Square.

Charles Renfro, who in 2004 became a partner at Diller and Scofidio's firm, told the New York Times that Scofidio's "voice is in all of" their projects, "both as a conceptual thinker and as someone who helped solve deep technical problems."

In 1999, the MacArthur Foundation awarded one of its famous "genius" grants to Scofidio and Diller, the first architects to receive the prestigious prize.

Scofidio is survived by Diller, as well as four children from a previous marriage, six grandchildren, and three great-grandchildren, according to the New York Times.