An oxygen concentrator at a Riverhead nursing home caught fire on April 15, prompting the evacuation of some residents from their rooms due to smoke conditions in part of the building. Riverhead firefighters responded to a call for a structure fire at Acadia Center for Nursing and Rehabilitation on Woodcrest Avenue shortly after 6 a.m. Tuesday. Firefighters quickly extinguished the fire in the oxygen concentrator machine with extinguishers, Riverhead Fire Department Chief Pete Kurzyna said. There were no serious injuries, though one resident and five staff members were transported to Peconic Bay Medical Center for treatment due to smoke inhalation, Riverhead Town Fire Marshal Andrew Smith said in a phone interview. Most of the residents of the A wing of the building, where the machine caught fire in a resident’s room, had to be evacuated due to smoke conditions, Kurzyna said. The fire department ventilated the wing to clear the smoke, the chief said. The fire was contained in the room where it started, Smith said. It did not do much damage to the room. The TRUAIRE-5 oxygen concentrator that caught fire was recalled by the manufacturer, the fire marshal said.