The nearly 2,000 workers renovating Maracana Stadium for the 2014 World Cup went on strike Thursday, citing unsafe conditions and demanding better pay and health care.

Maracana, one of the world's great soccer stadiums, is to host the World Cup final as well as the 2013 Confederations Cup.

Union leader Nilson Duarte said Thursday the work stoppage began after a worker broke a leg Wednesday when a barrel filled with chemical products exploded. Workers are expected to meet with employers later Thursday and decide whether to continue striking Friday.

Maracana is being overhauled not only for the two soccer events but the 2016 Olympics in Rio. Its roof will be replaced and the rest of the stadium is being upgraded.

Maracana had been renovated for the 2007 Pan American Games but needed a more extensive upgrade to meet the requirements of FIFA and the International Olympic Committee. It is expected to be ready only a few months before the 2013 Confederations Cup and will cost about $590 million, nearly $200 million more than the original estimate.

Workers renovating Mineirao Stadium in Belo Horizonte briefly went on strike this year over better conditions.

The slow pace of stadium construction is one of the main concerns as Brazil prepares for the World Cup, along with the lack of airport infrastructure. Authorities and organizers have guaranteed everything will be ready in time.