Tragedy struck Thursday on the set of Sylvester Stallone's film 'The Expendables 2' when one stuntman was killed and another was seriously wounded.

The accident happened during a stunt involving a bomb explosion in an inflatable boat at the Ognyanovo dam, about 15 miles outside the Bulgarian capital of Sofia.

In a statement, Nu Image/Millennium Films, the production company behind the film, said, "Our hearts go out to the families and those on the production affected by this tragedy. The filmmakers are working closely with the authorities in responding to and investigating this accident."

Stallone, the director of the first 'Expendables' film and the producer of the sequel, was shooting scenes elsewhere and was not present at the time of the accident.

In response to the incident, Arnold Schwarzenegger, a cast member in the new film, tweeted, "Everyone I met on the stunt team on The Expendables 2 was a joy to work with. My thoughts & prayers are with the families and the crew."

More From TSM Interactive