SAO PAULO -- Part of the stadium that will host the 2014 World Cup opener in Brazil collapsed on Wednesday, killing at least two people and causing significant damage, authorities said.
Former Corinthians president Andres Sanchez told a news conference that two people were confirmed dead. Local media reported a third person was hospitalised in serious condition. A fire department official had said earlier that three people had died.
The accident happened at lunchtime, so not many workers were on site when the crane collapsed on top of the metal structure.
Television images showed that part of a 500-ton metal structure cut through the outer walls of Sao Paulo's Itaquerao Stadium, destroying some of the seats on the east side of the venue and crashing into a massive LED panel that runs across the stadium's facade.
The accident could further delay delivery of the stadium, which was practically finished before Wednesday's collapse. FIFA has set a December deadline for all 12 World Cup venues to be ready.
The venue is scheduled to host other five matches, including a semifinal. It was initially expected to be built for the Confederations Cup this year, but delays with financing for the venue prompted authorities to scrap the stadium from the World Cup warm-up tournament.
It was not the first problem with World Cup stadiums in Brazil.
One worker died during construction of a stadium in the capital Brasilia last year and another in the Manaus venue in March. Also in March, heavy rains flooded the construction site of the Maracana Stadium, forcing the cancellation of a FIFA inspection visit at the time. In May, a small part of the roof at the Salvador stadium fell in after it was not able to sustain the large amount of water that settled on top of it.
The Sao Paulo stadium, which cost nearly $360 million, will seat nearly 70,000 people for the opener on June 12, when Brazil will play. About 20,000 seats will be temporary and installed only for the World Cup.
FIFA president Sepp Blatter sent a message of concern via Twitter.
I'm deeply saddened by the tragic death of workers @Corinthians arena today. Our heartfealt condolences are with the families.
— Joseph S Blatter (@SeppBlatter) November 27, 2013
"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," FIFA said in a statement on Wednesday.
Constructor Odebrecht said it was already investigating what happened.
A statement on the website of Corinthians -- the club which owns the stadium -- read: "The board of Sport Club Corinthians Paulista deeply regrets the accident earlier in Corinthians Arena."
FIFA secretary general Jerome Valcke said he was "extremely shocked by the news from Sao Paulo."
"Our thoughts are with the families of the victims of this accident," he said.
Information from The Associated Press was used in this report.