Suffolk County police say Christopher Torres was driving his 2008 Nissan west on Horseblock Road in Yaphank when he lost control of the car around 7:30 p.m. Saturday.
The car crossed into the eastbound lane near Yaphank Avenue and hit a van and another car.
A passenger in Torres' car died at the scene. She was 22-year-old Kaitlyn Dougherty of Medford.
Police say Torres is hospitalized in critical condition. He's 23 and from Nesconset.
The drivers of the other vehicles are being treated for non-life-threatening injuries. So is a passenger from one of those cars.
Police are investigating what caused the wreck.