Business interruption insurance policies usually contemplate the loss of premises by physical damage.  Typically, the Covid 19 pandemic does not physically damage premises, however, the loss of uses of premises is arguably “physical damage”.  In a decision released 30 March 2020 the Ontario Supreme Court in MDS Inc & anor v Factory Mutual Insurance Company, 2020 ONSC 1924  decided that loss of use or function of premises could be “physical damage” for the purposes of the insurance policy.  To interpret “physical damage” as requiring tangible damage was inconsistent with the purpose of the insurance policy.  The case involves the pre-emptive shut down of a nuclear reactor with a heavy water leak that produced isotopes that were then sold by MDS.  It claimed lost profit of about $121M by reason of the regulator imposed shutdown of the premises for 15 months.  This decision will be helpful to insureds in bringing successful claims for losses as result of Covid 19 enforced closures and losses.