Fifa has expressed its shock after two construction workers died in an accident at the Itaquera Stadium in Sao Paulo, which is due to host the opening match of next year’s World Cup.

A crane collapsed on Wednesday, killing Fabio Luiz Pereira and Ronaldo Oliveira dos Santos.

The news was released by the website of Corinthians, the Brazilian team who will move into the stadium when it is completed.

The accident casts a pall over the preparations for next year’s World Cup, which have already been criticised for their slow pace and chaotic management.

The entire notion of the rectitude of Brazil hosting the World Cup has already been hotly debated, and the loss of life will not go without mourning in Brazil.

Also under fire for the conditions workers must endure as Qatar prepares to host the 2022 World Cup, Fifa has released a statement on yesterday’s tragedy.

 "Extremely shocked by the news from Sao Paulo. Our thoughts are with the families of the victims of this accident," Jerome Valcke, Fifa's general secretary, tweeted.

"We are currently awaiting further details from the authorities, who are investigating this tragic accident."

A further statement read: "Fifa and the LOC [local organising committee] have learnt of the death of workers at the Corinthians Arena site in São Paulo with great sadness. We wish to send our heartfelt condolences to the family of the workers who tragically died today.

"The safety of workers is the top priority for Fifa, the LOC, the federal government. We know the safety of all workers has always been paramount for all the construction companies contracted to build the 12 Fifa World Cup stadiums.

"The local authorities will fully investigate the reasons behind such a tragic accident."