A crane lifting a section of roof into place toppled over, damaging the 65,000-capacity Arena Corinthians, which is due to host the tournament’s opening match on 12 June, and hospitalising a third man.
Many more might have died or been injured had most of the construction workers not been on a lunch break, according to Brazilian reports.
Local officials said they hoped the stadium would still be able to fulfil its six scheduled World Cup games, although it seems certain to miss governing body Fifa’s completion deadline next month.
“It’s impossible to make any forecasts at this moment,” said local organising committee chief Ricardo Trade. “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.”
Fifa has demanded that all 12 new World Cup stadia be finished by the end of the year but made no comment yesterday on the impact the accident would have on its schedule, only expressing condolences.
It is the latest setback to hit Brazil’s preparations, with construction of other venues at risk of over-running and repeated outbreaks of civil unrest over public money being spent on the tournament.
This was the third fatal accident to beset construction of a World Cup stadium in the country over the last two years, taking the death toll to four.
Arena Corinthians, known locally as Itaquerao, cost £218m and had been 94 per cent complete, according to constructors Odebrecht. It is one of six World Cup grounds still to be finished.
The tournament draw takes place next week, on Friday 6 December, and time is running out for builders, as a number of test events are usually necessary before a venue can be deemed safe for full use.
Current world club champions Corinthians are set to inherit the stadium, which is due to host one of the semi-finals, after the tournament. The team yesterday declared seven days of mourning for the two men.