MOSCOW -- A metal support beam at a stadium being built for the 2018 World Cup in the Russian city of Volgograd collapsed on Wednesday during construction work, the company contracted to oversee construction of the arena said.
The extent of damage to the stadium was not immediately clear, though the Stroytransgaz company said World Cup preparations would remain on schedule.
The beam collapsed under the weight of concrete being poured, but no one was injured, Stroytransgaz civil construction director Valery Nelyubov said in an e-mailed statement.
"A working commission has been created to examine what has happened," Nelyubov said.
"It is probably related to so-called metal fatigue. It is also not being ruled out that a mistake was committed" by workers from another company, he added.
The collapse follows two incidents in recent months at the construction site which reportedly left a total of three workers needing treatment for various injuries.
The 45,000-capacity Volgograd stadium is scheduled to hold four group stage games during the 2018 World Cup.