It happened just before 2 a.m. Saturday, June 8, in Medford.
A tractor-trailer was traveling northwest on Horseblock Road and attempting to make a left turn onto Express Drive North when it was struck by a 2008 BMW, Suffolk County Police said.
The driver of the BMW fled on foot.
One passenger in the BMW was pronounced dead at the scene by a physician assistant from the Office of the Suffolk County Medical Examiner. The person's identity has not yet been released.
The other passenger was airlifted via Suffolk County Police helicopter to Stony Brook University Hospital for treatment of serious injuries.
The driver of the tractor-trailer was not injured.
The driver of the BMW is described as a Hispanic male wearing a dark-colored shirt and tan shorts.
Both vehicles were impounded for safety checks.
Detectives are asking anyone with information on this crash to call the Major Case Unit at 631-852- 6553 or call anonymously to Crime Stoppers at 1-800-220-TIPS.
Check back to Daily Voice for updates.
Click here to follow Daily Voice Ronkonkoma and receive free news updates.