To Catalans in particular, and to Spanish opera lovers, it was as though a part of the nation's artistic soul had been torn out. The theatre, with its Palladian facade overlooking the renowned Las Ramblas avenue, was one of the world's largest and a training ground for Carreras and Caballe. It erupted in flames in mid-morning, possibly ignited by sparks from workmen who were soldering scenery backdrops for its latest opera.
Around 180 people were in the mid-19th-century theatre, including a group of schoolchildren on a tour, when the fire broke out. Miraculously, all were evacuated in time and the only casualties were two firemen who suffered from smoke inhalation. Although firemen were rapidly on the scene, the Liceu's wooden roof collapsed and made control of the blaze impossible. It was all over within four hours.
Distraught members of the theatre's orchestra had begged firemen to rescue their instruments but all were lost. Its 19th-century paintings were, however, saved.
'The Liceu is destroyed but not dead,' said the Deputy Prime Minister, Narcis Serra, himself a Catalan, who had rushed to the scene along with the Culture Minister, Carmen Alborch. 'It will be reconstructed on the same site, in the same style.' Catalonia's regional Presidente (Prime Minister), Jordi Pujol, visibly moved, made a similar pledge.
'It's one of the jewels of Barcelona,' said Alberto Mora, a 32-year-old flautist and one of 200 musicians and other artists who gathered on Las Ramblas to comfort one another as the building burned. Caballe, who in recent years had fallen out with the theatre's artistic director and had refused to sing there, was more sanguine. 'Everybody knew a disaster could happen. Ever since I was first there in the Sixties, they had been trying to get something done about the stage,' she said.
Mr Mora agreed that the danger had been apparent. 'For some time people have been saying something like this could happen. There was a lot of wood and a lot of lights,' he said. A plan to overhaul the theatre, at a cost of around pounds 19m, was due to start next year with a view to a grand re-opening to mark its 150th anniversary in 1997.
When inaugurated in 1847, with a capacity of 3,500, the Liceu was the biggest theatre in the world. It was built with the money of the thriving upper-middle classes and many boxes still belonged to wealthy families and were decorated with their own furniture or even art works.
In 1893, an anarchist, Santiago Salvador, tossed a bomb into the audience during a performance of Rossini's William Tell, killing 20 opera lovers. Fierce repression followed and Salvador was publicly garroted.
The Liceu was first gutted by fire in 1861 and was rebuilt within a year. Caballe ventured that, with modern technology, the Catalans should be able to rebuild it even more rapidly than their great-grandparents. But its 19th-century character has surely been lost for ever.