A retired NYPD detective shot and wounded his two adult sons, then killed himself during a party at a Bellport home Sunday night.

Police say it happened during a family gathering at a home on Foxglove Circle, in the gated community of Atlantic Point. After a family fight broke out, police say 61-year-old Irvin Noak retrieved his handgun from a bedroom and opened fire on his sons before turning the gun on himself.

The sons, 30-year-old Irvin Noak III and 22-year-old Aaron Noak, were taken to Brookhaven Memorial Hospital in critical condition.

No one else was injured.

Neighbors say the family party had initially appeared peaceful, and the elder Noak seemed happy earlier in the day.

Investigators say the injured sons were apparently trying to break up the fight when they were shot by their father.

It's not clear what the fight was about.

Authorities say Noak was a New York City detective for almost 30 years.