At 8:30 a.m. Sunday, power went out at Johnson Memorial Medical Center. Normally this wouldn't be a problem. Power comes from two Connecticut Light & Power Co. sources -- one in Stafford, one in Somers. But Sunday, power feeds on both sides of the hill where the hospital is located failed, and the approaching Tropical Storm Irene kept utility workers from getting there to fix the problem. It was the first event in a day that would end with a full evacuation of the hospital, an unprecedented move that took 4 1/2 hours and relied on the cooperation of several area hospitals, state officials, and emergency workers in surrounding towns. Transporting all 43 patients -- a logistically and emotionally fraught process -- took the efforts of 23 ambulances, some from as far as New Haven, most making two trips each. Patients were taken to St. Francis Hospital and Medical Center in Hartford and Hartford Hospital, as well as hospitals and health centers in Manchester, Vernon, New Britain and Hebron. As at other Connecticut hospitals, officials and staff at Johnson Memorial spent much of last week preparing for Hurricane Irene. They made sure that there were enough medical supplies and food, arranged for extra staff and tested the generator. None of which was enough Sunday. Ten seconds after power went out, the hospital's generator took over, and operations continued as normal until 3:30 p.m. That's when the generator failed.