Question: When was the architect behind the Calatrava bridge born? 
Context: Santiago Calatrava Valls (born 28 July 1951) is a Spanish architect, structural engineer, sculptor and painter, particularly known for his bridges supported by single leaning pylons, and his railway stations, stadiums, and museums, whose sculptural forms often resemble living organisms.  His best-known works include the Milwaukee Art Museum, the Turning Torso tower in Malmö, Sweden, the Margaret Hunt Hill Bridge in Dallas, Texas, and his largest project, the City of Arts and Sciences and Opera House, in his birthplace, Valencia.  His architectural firm has offices in New York City, Doha, and Zürich. The Lincoln Road–Pine River Bridge, also known as the Riverdale Bridge, was a bridge located on Lincoln Road over the Pine River near Seville, Michigan.  The architect behind the Lincoln Road–Pine River Bridge was the Michigan State Highway Department and its builder was Walter Willets.  The bridge is notable for being a large early example of an arched through girder bridge in Michigan, and for sitting on substantially skewed abutments.  It was listed on the National Register of Historic Places in 1999. The Bac de Roda Bridge, known locally as the Calatrava bridge, is a road bridge that links the districts of Sant Andreu and Sant Martí in the city of Barcelona, Catalonia, Spain.  The bridge was constructed between 1984 and 1987, to a design by Santiago Calatrava, as part of the preparations for the 1992 Summer Olympics. Trinity Bridge is a three-way footbridge which crosses the River Irwell and links the two cities of Manchester and Salford in Greater Manchester, England.  It was designed by renowned Spanish architect, Santiago Calatrava and was completed in 1995.  It was one of Calatrava's earliest bridge works and remains the only project he has completed in the United Kingdom. Several bridges by the architect Santiago Calatrava are known locally as Calatrava bridge or Calatrava's bridge.  These include: Jan Kaplický ( ; ] ; 18 April 1937 – 14 January 2009) was a world-renowned Neofuturistic Czech architect who spent a significant part of his life in the United Kingdom.  He was the leading architect behind the innovative design office, Future Systems.  He was best known for the neofuturistic Selfridges Building in Birmingham, England, and the Media Centre at Lord's Cricket Ground in London. The Chords Bridge (Hebrew: גשר המיתרים‎ ‎ , "Gesher HaMeitarim"), also called the Bridge of Strings or Jerusalem Light Rail Bridge, is a side-spar cable-stayed bridge in Jerusalem, Israel.  The structure was designed by the Spanish architect and engineer Santiago Calatrava and is used by Jerusalem Light Rail's Red Line, which began service on August 19, 2011.  Incorporated in the bridge is a glass-sided pedestrian bridge enabling pedestrians to cross from Kiryat Moshe to the Jerusalem Central Bus Station.  The bridge, which cost about $70 million (NIS 246 million), was inaugurated on June 25, 2008. The Assut de l'Or Bridge (Valencian: "Pont de l'Assut de l'Or", Spanish: "Puente de l'Assut de l'Or") is a dazzling white single-pylon cable-stayed bridge, designed by Valencian architect and civil engineer Santiago Calatrava, and completed in December 2008.  The name "l'Assut de l'Or" means "the Dam of the Gold" and refers to a dam that was formerly located nearby - although locally it is referred to as "El Jamonero" (The Ham Holder)!  The bridge is called the Serreria Bridge by its designer, Santiago Calatrava. Tom Aidala (December 23, 1933, New York – January 22, 2016, Kelseyville, California) was an American architect.  He was the principal architect behind the revitalization of downtown San Jose, California.  His projects included pedestrian bridges over the Guadalupe River, the Circle of Palms near the Fairmont San Jose, and the Paseo de San Antonio transit station.  He was employed by the San Jose Redevelopment Agency between 1983 and 1998.  An avowed Modernist, he wrote "Thou shalt not allow one more mansard roof in San Jose." The Ponte della Costituzione (English: Constitution Bridge ) is the fourth bridge over the Grand Canal in Venice, Italy.  It was designed by Santiago Calatrava, and was moved into place in 2007 (connecting Stazione di Santa Lucia to Piazzale Roma), amid protest by politicians and the general public.  The bridge was installed in 2008 and opened to the public on the night of September 11, 2008.  The bridge was known as "Quarto Ponte sul Canal Grande" before the official name was adopted to celebrate the 60th anniversary of the Italian constitution in 2008.  Tourists and locals in Venice now refer to it as the Calatrava Bridge (Italian: "Ponte di Calatrava" ).
Answer: 28 July 1951