Brasilia, August 14 (Xinhua-RHC) -- Brazil's President Dilma Rousseff has declared three days of official mourning following the unexpected death of Socialist Party presidential candidate Eduardo Campos.

"All of Brazil is in mourning, we lost a great Brazilian, we lost a great colleague," Rousseff said of Campos, who died in a plane crash yesterday.

The plane in which Campos was traveling crashed over several houses in a residential neighborhood in Santos. According to the Brazilian Air Force, the plane went down as it was preparing to land, and bad weather is likely to be the cause of the accident.

Campos had been politically active since youth, first as a federal deputy, then as minister and twice governor of Pernambuco state. He was running in distant third place in the lead up to the October 5th general elections, behind Rousseff and Aecio Neves of the Brazilian Social Democratic Party.

During the previous presidency of Luiz Inacio Lula da Silva, Campos served as Science and Technology minister, and was considered a politician with a promising future.

He was from a traditionally political family in Brazil -- his maternal grandfather Miguel Arraes was an icon of the left-wing in Brazil and also served as Pernambuco governor. In a bizarre coincidence, Campos died on the same day as his famed grandfather, August 13th. This was Campos' first attempt at a presidential race.