It happened just before 10 p.m. Monday near exit 49S in Melville.
Police say the driver of a Honda Civic hit a Mazda SUV, forcing both off the roads and into the woods.
A 19-year-old passenger, Josue Melendez-Florez, was killed.
Two passengers in the Honda, a 14 year old and an 18 year old, were hurt.
They are in critical condition this morning.
Both drivers were being treated for non-life-threatening injuries.
ALSO READ | Exclusive: Family speaks after boy, grandmother critically hurt in NJ hit and run
* More Long Island news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube
Submit a News Tip