On 12 April 2001, portions of Toronto’s Skydome’s retractable roof collided when it was being opened. Pieces of the roof fell onto the playing field, making the Skydome unsafe for use. The regularly scheduled Major League Baseball game between the Toronto Blue Jays and the Kansas City Royals was postponed. The Blue Jays sued Sportsco, the owner/operator of the Skydome, for damages in the amount of $1 000 000, alleging a loss of revenues from the loss of use of the building on 12 April 2001. Sportsco made a claim under its Comprehensive General Liability Policy with ING Insurance for a defence to the Blue Jays’ claims. ING denied coverage and brought an application seeking a declaration that it did not owe Sportsco a defence (Note: an insurer has a duty to defend the insured when allegations fall within the coverage of the policy). Who has the onus of proving whether a claim falls within an insurance policy? On what basis may an insurance company like ING Insurance deny coverage to an insured?