Raymond and claire Lagrandeur, of Garson, are pictured with their three children. Denise, 5, Joanne, 2, and Raymond, six months. Their three-year-old son, Richard, was the youngest of 22 persons who died in Sudbury General Hospital during a 3 1/2-month period last year. An inquest opens in Sudbury on Monday. The inquiry follows discovery that oxygen and nitrous oxide anesthetic lines may have been mixed up in an emergency treatment area of the hospital.