Gas gangrene occurs when infection develops deep inside the body, such as inside muscles or organs, usually as a result of trauma. The bacteria that causes gas gangrene, called clostridia, release dangerous toxins or poisons that wreak havoc throughout the body, along with gas which can be trapped within body tissue. As the condition progresses, the skin may become pale and gray, and make a crackling sound when pressed, because of the gas within the tissue. Gas gangrene warrants immediate medical treatment. Without treatment, death can occur within 48 hours.