Assume a passenger dies aboard an international flight, and that there was no defibrillator aboard the aircraft that might have been used to revive him. Do you think the failure to have a defibrillator is an event "external to the passenger?" Do you think it is an "unexpected or unusual" event? Would it make a difference if there was a legal requirement to have a defibrillator aboard, or that it was or was not industry practice to do so?