Firefighters were called to a report of an explosion on the sixth floor of the hospital around 2:15 a.m., Durham Fire Department spokeswoman Sierra Jackson said. The firefighters discovered there had been no explosion and the fire had been extinguished by the hospital sprinkler system.
The cause of the fire was still under investigation, Jackson said later Tuesday morning.
Hospital officials were still investigating exactly where the fire occurred and how, said Katie Galbraith, hospital chief of operations.
The hospital was operating normally several hours later.
Other patients in the 30-bed, long-term care unit, a separately licensed facility operating as Select Specialty Hospitals, were moved to other parts of the hospital.
Some other patients were moved because of flooding caused by the sprinklers.
"They are safe and they are being well cared for," Galbraith said.
The three slightly injured patients all had been on ventilators prior to the fire. They were taken to the emergency room to be checked for smoke inhalation and then sent to the intensive care unit.
The names of the victim and those injured were not immediately released.
Galbraith said the hospital staff practices for just such emergencies.
"Our focus is on making sure people are safe," she said. "They did exactly what they're trained to do."
Durham Regional is a 369-bed acute care hospital.