Prague - Czech born architect Jan Kaplický died Tuesday night aged 71.
According to Czech press agency ČTK he collapsed in the street near Vítězné square in Prague. Medics from emergency service were not able to save his life. The Czech police did not immediately comfirm the identity of the deceased.
The world renowned architect died on the same day his wife Eliška gave birth to their daughter Johanka.
Jan Kaplický was an author of the design for the National Library's new building that was originally planned for Prague's Letná Park but later ran into the opposition of the city's leadership.
Among the most vocal critics were mayor of Prague Pavel Bém and Czech president Václav Klaus.
"Last two years of Jan Kaplický's life have been embittered by people who will have left no legacy.
Sadly, Jan Kaplický became yet another Czech cultural figure that was done in by Czech narrow-mindedness," National Library's former director Vlastimil Ježek said for Czech TV as his first reaction.
Kaplický won an international competition with his design, which became popularly known as the Blob or the Octopus. It would have been the architect's first design realised in his native city.