of the album, the band toured extensively, opening for Slayer and Metallica before making their way to the second stage of Ozzfest. Following Ozzfest, they toured with Fear Factory and Incubus before headlining the Sno-Core Tour with Puya, Mr. Bungle, The Cat and Incubus providing support. In November 1998, System of a Down appeared on South Parks Chef Aid album, providing the music for the song "Will They Die 4 You?" Near the end of the song, Tankian can be heard saying, "Why must we kill our own kind?" a line that would later be used in the song "Boom!" Although System of a Down is credited on the album, South Park character Chef does not introduce them as he does most of the other artists featured on the record. Toxicity and Steal This Album! (2001–2003) On September 3, 2001, System of a Down planned to launch their second album at a free concert in Hollywood as a "thank you" to fans. The concert, which was to be held in a parking lot, was set up to accommodate 3,500 people; however, an estimated 10,000 to 15,000 fans showed up. Due to the large excess number of fans, the performance was canceled by fire marshals just before the group took the stage without announcement of the cancellation. Fans waited for more than an hour for the group to appear, but when a banner hanging at the back of the stage that read "System of a Down" was removed by security, the audience rushed the stage, destroying all the band's touring gear (approximately $30,000 worth of equipment) and began to riot, throwing rocks at police, breaking windows, and knocking over portable toilets. The riot lasted six hours, during which six arrests were made. The band's manager, David "Beno" Benveniste, later said that the riot could have been avoided if the group had been permitted to perform or had they been allowed to make a statement at the concert regarding the cancellation. System of a Down's scheduled in-store performance the next day was cancelled to prevent a similar riot. The group's big break arrived when their second album, Toxicity, debuted at No. 1 on the American and Canadian charts. The album has eventually achieved 3x multi-platinum certification in the United States. It was still on top in America during the week of the 9/11 attacks and the political environment caused by the attacks