Officers responded to a residential fire on Arlington Street at around 7:48 a.m., where they found the home fully engulfed in flames.
Firefighters from the Westbury Fire Department, assisted by several neighboring departments, extinguished the blaze. About 50 firefighters responded to the scene.
Authorities said the victim was discovered inside the residence and pronounced dead at the scene.
Before firefighters arrived, a Village of Hempstead fire chief, who is also a Nassau County fire marshal, and another fire marshal who was on his way to work, along with Nassau County police officers, attempted to enter the burning home to rescue the trapped occupant. Officials described the effort as "valiant," but it was unsuccessful.
No other civilians or firefighters were injured.
The fire was brought under control in about 45 minutes. The home sustained significant damage, and the Town of North Hempstead Building Department will evaluate the structure.
The American Red Cross is assisting three adults who were displaced by the fire.
The Nassau County Police Department's Homicide Squad, Arson/Bomb Squad and the Nassau County Fire Marshal responded to the scene. The cause of the fire remains under investigation.
No additional information has been released.
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