A second worker has died at the Arena Amazonia in Manaus, which will host Italy-England in the World Cup.
On Saturday morning a 22-year-old died when he fell around 35 metres, as a cable snapped while he was working on the construction of the roof.
Only a few hours later, Brazilian media reported a 49-year-old, Jose Antonio da Silva Nascimento, also died at the stadium.
He suffered a heart attack while performing construction work and his family complained there was a delay in treatment as well as excessive working hours that contributed to his death.
Workers involved in the 2014 World Cup are now threatening to go on strike unless there are improvements in safety procedures.