A teen was killed and seven other people were sickened Thursday by carbon monoxide poisoning in a Mastic Beach home.

According to police, the source of the carbon monoxide was a gas-powered generator that was running in the home?s unventilated basement to provide electricity. The family reported that the electricity at the home had been turned off Wednesday.

Emmanuel Cassaberry, 19, was pronounced dead at Brookhaven Memorial Hospital in Patchogue. His family members were also transported to the hospital. His stepfather, 42-year-old Steven Vaughn, mother, 39-year-old Cheryl Cassaberry, and brother, 22-year-old Peter Cassaberry, were transported from Brookhaven Memorial Hospital to John T. Mather Hospital in Port Jefferson for further treatment.

Shaniece Cassaberry, 11, Shawan Vaughn, 10, Shalana Vaughn, 7, and Shanelle Vaughn, 22 months, were treated at Brookhaven hospital and released.

LIPA officials said power was shut off because payments were six months behind. LIPA representatives claim they repeatedly sent warnings by phone and mail. According to the utility, a LIPA employee went to the home Wednesday to deliver the warning in person.

AP wire reports contributed to this story.