The accident occurred in the Spanish capital's tourist quarter on Tuesday. Ten people were injured in the accident at the construction site. Most of the injuries were minor.
The official information about the missing comes from Francisco Martín Aguirre, who is the representative of the Spanish central government in Madrid.
We could not see anything, (the air) was filled with rubble dust, it was not possible to breathe, said the construction site's foreman on site to the Spanish newspaper El País.
The accident occurred in the city district with the city's large opera and near the square Puerta del Sol.
