The Riverhead Fire Department put out a basement fire at a home on the corner of Maple and Second streets early Thursday morning, officials said.
The blaze was the result of an oil burner malfunction, reported at 4:25 a.m. Thursday, according to a Riverhead FD press release.
Fire officials said a large amount of smoke and high levels of carbon monoxide were found inside the basement.
Each of the residents were evacuated from the home safely and checked for carbon monoxide poisoning, officials said.
The fire was extinguished, fans were used to remove the smoke and the scene was turned over to the fire marshal about 5:30 a.m.