Hong Kong will review the age threshold of elderly residents in need to better identify priority cases and prevent more tragedies from happening, the welfare chief has vowed following the latest suicide by an elderly resident.Secretary for Labour and Welfare Chris Sun Yuk-han made the pledge on Saturday after a 70-year-old man was found hanging in his flat in Lai King Estate the day before.Police said the man’s wife, 78, was found unconscious in the bedroom with her head covered by a quilt....