A second unit crew on the set of the upcoming Expendables sequel were filming an explosion special effect when tragedy struck killing one stuntman and critically injuring another. The stuntman were reportedly in a rubber boat at the top of Bulgaria’s Ognyanovo water reservoir when reportedly the bomb accidentally detonated. One stuntman died instantly the other was critically injured and their names have not been released pending an investigation. The actors and the rest of the crew were hundreds of miles away filming in Bansko so there were no injuries among them. Authorities are still investigating the accident and a formal report will be out soon.