Carbon monoxide from a generator apparently killed a teenager and sickened seven of his relatives after the power was shut off at their suburban home because of overdue payments, authorities said Thursday.

Emmanuel Cassaberry, 19, was pronounced dead at Brookhaven Memorial Hospital in Patchogue. The hospital was evaluating the conditions of his parents and five siblings, the youngest a 1-year-old, police said.

The incident occurred in a quiet, tree-filled neighborhood of middle-class homes on eastern Long Island.

"It's horrible. On your own block. It's horrible, you know?" said neighbor Eileen Miller.

"My heart goes out to them," said another neighbor, Ed Oliver. "From what I know, they were very kind people. I always used to wave to the father. The father always used to drop his children right here at this bus stop."

On Thursday afternoon, the house's windows were thrown open, with curtains askew in the front. Yellow police tape surrounded the property, which included a wooden swing set out back. A red sport utility vehicle was parked in the driveway, next to a car on blocks, covered with a blue tarp.

The property's appearance -- a faded brown, brick-and-shingles ranch house and an overgrown yard -- was a sharp contrast to the rest of the well-kept block. Across the street, an American flag was displayed at a house with a meticulously manicured lawn.

Investigators found indications that the gasoline-powered generator had been used in the basement, according to Lt. Jack Fitzpatrick, commander of the Suffolk County police homicide squad.

Bert Cunningham, spokesman for the Long Island Power Authority, said the power was shut off Wednesday afternoon because payments were six months behind. Cunningham said the utility repeatedly sent warnings by phone and mail, and a LIPA employee went to the home on Wednesday to deliver the warning in person.

"This is a real tragedy," said LIPA CEO Richard Kessel. "Even though we went through every step to try to help them keep service and we know it is not our fault, your heart still aches for them."

Mastic Beach is about 65 miles east of Manhattan.