The stadium, which was scheduled to be finished in the next month or so, is to be the site of the opening game and five other matches when Brazil hosts the World Cup in June and July next year. A spokesman for the São Paulo fire department yesterday confirmed the two deaths, both construction workers. Local media said a crane was lifting a piece of the roof into place when the accident occurred, sending the part crashing down on to the side of the structure. Brazil has struggled to deliver stadiums, public transport improvements and other World Cup-related projects within the timelines specified by football’s world governing body, Fifa. Some construction sites, such as a new terminal at São Paulo’s international airport, have teams working on them around the clock seven days a week to try to finish them before the event. The São Paulo stadium – formally called Arena Corinthians but known locally as Itaquerão, for the area where it is located – was 94 per cent complete at the time of the accident, according to the stadium’s website. Photos appeared to show significant damage to the exterior, and it was not clear if the damage could pose a major delay to opening the stadium, according to Ricardo Trade, executive director of the local organising committee for the World Cup. “It’s impossible to make any forecasts at this moment,” he said. “At the same time, we can’t think that if [construction] is delayed by three months, the stadium will end up out of the World Cup.” Corinthians, the professional club that will play in the stadium after the tournament, lamented the accident in a statement. “Extremely shocked by the news from Sao Paulo,” Fifa’s executive secretary Jerome Valcke wrote on Twitter. “Our thoughts are with the families of the victims of this accident.” He added: “We are currently awaiting further details from the authorities, who are investigating this tragic accident.” The incident is a further blow to Brazil’s image and its preparations to host the 2014 tournament. Six stadiums were used in the Confederations Cup warm-up tournament in June this year, but several of them were delivered later than Fifa wanted. Another six, including Itaquerão, are due to be delivered by the end of December, but all indications are that at least two, in Manaus and Cuiabá, will not be ready on time. The accident also casts further scrutiny on Brazil’s building standards. One worker was killed earlier this year while working on Palmeiras’ new stadium, also in São Paulo. And the Engenhão stadium in Rio de Janeiro, built for the 2007 Pan American Games, was closed in June after engineers said the roof was in danger of collapsing in high winds. The arena is due to be used as the Olympic stadium in 2016. It will now be closed for 18 months for repairs. The Itaquerão stadium was originally budgeted at 350 million reals (about £92.6m) but that shot up to over one billion reals (£264m) after local authorities decided to hold the prestigious opening match there. Former Corinthians president Andres Sanchez said Fifa’s demands for more lifts, leather seats and extra space for sponsors were among the reasons for the massive cost increase.