Between June 1980 and March 1981, the cardiac ward at Toronto's Hospital for Sick Children experienced a dramatic 616% leap in infant mortality, with the number of actual deaths estimated between 21 and 43 babies in various police and media reports. The first "suspicious" death was that of 18-day-old Laura Woodcock, lost June 30, 1980. Two months later, after 20 deaths, a group of nurses on the ward voiced their concern to resident cardiologists, and a fruitless investigation was launched on September 5, in the interest of resolving "morale problems." Still, the deaths continued, and on March 12, 1981, a staff physician aired his personal suspicions in a conversation with Toronto's coroner. An autopsy of the latest victim , 27-day-old Kevin Garnett, found thirteen times the normal level of digoxin -- a drug used to regulate heart rhythm, itself fatal if taken in too large a dose. On March 21, following more deaths and discovery of elevated digoxin levels in two more corpses, the coroner met with detectives and hospital administrators in an emergency session. Members of the cardiac nursing team were placed on three days leave while officers began to search their lockers, comparing work schedules with the dates and times of suspicious deaths. On March 22, with locker searches under way, another baby died on the cardiac ward at Sick Kids. Justin Cook is generally named as the last victim in a bizarre string of slayings, his death attributed to a massive digoxin overdose, deliberately inflicted by persons unknown. Three days later, police arrested nurse Susan Nelles on one count of murder, adding three identical charges to the list on March 27. As "evidence" of her involvement in the crimes, officers referred to certain "odd" remarks and facial expressions mentioned by other nurses, noting that 24 of the suspicious deaths occurred on Nelles's shift, between 1 and 5 a.m. With Nelles on leave pending trial, bizarre events continued at the hospital. In September 1981, nurse Phyllis Trayner found capsules of propanolol -- another heart regulator -- in the salad she was eating for lunch, and a second nurse spooned more pills out of her soup. Administrators had no explanation for the incident, and rumors flourished of a "phantom" or a "maniac" stalking the hospital corridors. A preliminary hearing in the case of Susan Nelles opened on July 11, 1982, with prosecutors citing 16 other "carbon copy" murders in addition to the four already charged. Four months later, on May 21, the pending charges were unconditionally dismissed, a presiding judge describing Nelles as "an excellent nurse" with "an excellent record." At the same time, he noted that five of the hospital deaths were apparently murders, committed by persons unknown. Fresh out of suspects, the state launched its first judicial probe of the case on May 25, requesting assistance from the Atlanta-based Center for Disease Control four months later. CDC's report on 36 submitted cases called 18 of the deaths "suspicious," with seven listed as probable homicide; another ten cases were "consistent" with deliberate digoxin poisoning , but there was insufficient evidence for a definitive conclusion. A new judicial inquiry was ordered on April 21, 1983, and Gary Murphy, six months old, died on the cardiac ward two days later, his passing notable for "elevated digoxin levels" discovered in post mortem testing. Murphy's death was excluded from the "official" list when hearings began on June 21, with testimony pointing vaguely toward a different suspect on the staff. By February 1984, cardiac nurses were voicing suspicions against Phyllis Trayner, one reporting that she saw Trayner inject infant Allana Miller's I.V. bottle with an unknown drug three hours before the baby died, on March 21, 1981. Trayner flatly denied all charges of impropriety, and the commission left her denials unchallenged, refusing to name a suspect in its January 1985 report. That document describes eight infant deaths as murders, while another 13 are listed as "highly suspicious" or merely "suspicious." At this writing, the Toronto case remains unsolved, the killer(s) still at large.