It happened around 5:45 p.m. Tuesday, May 14, in Flanders.
Southampton Town Police said that a vehicle traveling northbound Route 104 left the designated travel portion of the road and crashed into a tree.
The operator and the passenger were both transported to an area hospital for further treatment.
The passenger later succumbed to his injuries. His identity is being withheld pending the notification of next of kin.
During the accident investigation, the road between the Route 31 traffic circle and Pleasure Drive was closed for over two hours.
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