Claimant's husband was employed as a shipping clerk. On July 8, 1950, he visited a physician complaining of tiredness, and the physician was of opinion he was then suffering from a heart condition. Four days later he complained to a fellow employee of feeling a "pain in his heart" after lifting and carrying heavy boxes. The lifting of boxes was part of his work, although it might be found that on this day the boxes were somewhat heavier than usual. He stopped work after this attack and died nine days later. There is medical opinion in the record that on the day of the attack he suffered a coronary occlusion and that there was association between the work on that day and the occlusion and subsequent death. The continuance of work after suffering a heart attack followed by a further heart attack in the course of the work has been regarded as sufficient proof of an "accident", since it identifies a definite physical event with the work. It has been regarded, if medically established, as a further injury to an already weakened physical structure. Here there is medical opinion that the decedent had a weakened heart before his attack in the course of his work and proof that there was connection between the work and the attack which seem to bring the case within the pattern of heart injuries which have been regarded as compensable accidents. Decision and award unanimously affirmed, with costs to the Workmen's Compensation Board.