Sao Paulo, Brazil (CNN) -- Brazilian presidential candidate Eduardo Campos died Wednesday when a small plane carrying him to a campaign stop crashed into a residential neighborhood, state media reported.
All seven people aboard the the Cessna 560XL were killed when the aircraft crashed in the coastal city of Santos, Brazil, about 40 miles south of Sao Paulo, state-run Agencia Brasil reported.
As the aircraft prepared to land, it swerved because of bad weather. The air traffic control tower immediately lost contact with the plane, Agencia Brasil said.
One witness, a pilot trainee, said he heard a loud noise and saw the plane flying low before it crashed into a house and then the ground.
It was pitched down at 70 degrees, and "hit the ground like a rock," Matheus Giovannini said.
Campos, 49, was a well known politician running in his first presidential election as a candidate for the Brazilian Socialist Party.
He was most recently the governor of Pernambuco state and was a federal lawmaker from 1998 to 2003. He was married and had five children.
An adviser, photographer, two pilots, and two others from Campos' political team were also killed in the plane crash.
A dozen people on the ground were injured when the plane crashed, Agencia Brasil reported.
Messages of mourning appeared on Campos' campaign website hours after the crash.
"We lost Eduardo Campos when Brazil most needed his patriotism, his selflessness, his fearlessness and his competence," said Roberto Amaral, the party's first vice-president. "It is not just Pernambuco and its people who lose their leader, not just the Brazilian Socialist Party that loses its leader. It is Brazil that loses a young and promising statesman."
Campos' death sent shock waves across the South American country's political landscape less than two months before the October 5 presidential vote, leaving supporters stunned and wondering who would replace him on the ballot.
Campos was among the serious contenders in the election, steady in third place in the polls at about 8%, according to pollster Datafolha. The two leading candidates are incumbent President Dilma Rousseff and center-right candidate Aecio Neves.
Eight other candidates are polling at 3% or lower.
According to Agencia Brasil, Rousseff will suspend her campaign for three days. Neves said on his Twitter account that he would also suspend his campaign activities.
"All of Brazil is in mourning. Today we lost a great Brazilian, Eduardo Campos. We lost a great friend," Rousseff said via Twitter.
Brazil's Superior Electoral Tribunal, which runs the country's elections, announced that Campos' coalition had 10 days to nominate a new candidate. Campos' vice presidential running mate, Marina Silva, a former senator and environmental minister, is also a well known politician with a solid base of supporters. She ran for president in 2010 for the country's Green Party.
The country's Air Force said Wednesday's plane crash was due to bad weather, but it is continuing to investigate the accident.
The plane had departed from Santos Dumont airport in Rio de Janeiro en route to Guaruja airport in Sao Paulo state, Agencia Brasil reported.
Its maintenance and inspection records were up to date, the state outlet said.
Shasta Darlington reported from Sao Paulo. Danny Guerra and Jason Hanna reported from Atlanta. CNN's Arthur Brice, Jessica King, Mariano Castillo and Catherine E. Shoichet contributed to this report.