"A piece of decor fell and killed a person during a show at the Bolshoi Theatre", a source told Sputnik.
The spectators said that the tragedy happened minutes into the Sadko opera. The show was stopped immediately, and they were ushered to the exits.
A preliminary probe into the incident was launched.
"The Investigative Committee's Tverskoy inter-district investigative department of the central administrative district in Moscow has opened a preliminary investigation", Yulia Ivanova, a senior committee official, said.