their first game at the new stadium, a preseason 41–19 victory against the Calgary Stampeders with 53,472 in attendance. A month later, on July 24, 1983, a crowd of 41,810 watched the BC Lions defeat the Saskatchewan Roughriders 44–28 in the Lions' first regular season game at the stadium. The venue would host the Soccer Bowl '83 later that year. On September 18, 1984 Pope John Paul II addressed an over-capacity crowd for "A Celebration of Life". The celebration was part of the papal visit to the Archdiocese of Vancouver. It was one of the most heavily attended events in the stadium. The Pope's Celebration of Life was followed a few months later by the Canadian Pacific Billy Graham Crusade, which drew similar numbers each night. The stadium was then used for the opening and closing ceremonies of the 1986 World Exposition on Transportation and Communication (Expo '86). Accepting an invitation by the Province of British Columbia, their Royal Highnesses Prince Charles and Princess Diana made themselves available to take part in the opening ceremonies. To great fanfare, they officially proclaimed the World's Fair open on May 2, 1986. In 1987, an exhibition match of Australian rules football was played at the stadium and drew a crowd of 32,789 a record for the largest AFL/VFL crowd outside of Australia. The stadium also held an NFL exhibition game in 1998 when the San Francisco 49ers beat the Seattle Seahawks 24–21 in the American Bowl. 2007 roof deflation On January 5, 2007, snow accumulated on the air-supported Teflon Fibreglass roof, despite strict zero accumulation of ice guidelines and ice accumulation structural warnings. The accumulation caused a tear in the roof's ETFE-coated fabric close to Gate G on the south side where the roof meets the top of the concrete bowl. The tear grew quickly as air escaped through it, whereupon maintenance staff performed an intentional, controlled deflation to protect the integrity of the roof's intact fabric panels. As it was designed to do, the deflated roof rested on its steel support cables 6 metres (20 ft) above the seating and the field. Normally, the roof had a rise of 27 metres (90 ft) above the top of the bowl when inflated. No one was injured during the incident, although rain and melted snow flooded the bowl and subsequently had to be pumped out. An independent report indicated that an accidental rapid pressurization