Despite numerous malpractice suits and warnings from their own doctors and staff that Stefan Konasiewicz posed a risk to patients, St. Luke's hospital continued to allow the neurosurgeon to practice. One possible reason: Konasiewicz, who worked at St. Luke's from 1997 to 2008, produced significant revenues for the hospital by performing more neurosurgeries than his peers in Duluth. And during Konasiewicz's time at St. Luke's, the hospital went from the red to the black, financial records obtained by the News Tribune show. "The assumption from many people was that St. Luke's didn't deal with him because he was bringing in so much revenue," said Suzanne Canfield, a retired surgical technician who worked in St. Luke's neurosurgery department. "Many physicians and anesthesiologists had concerns about him right from the beginning. But what bothered me was that administration didn't address them," she said. "At least, nothing ever changed."