The incident happened just before 10 a.m. in Riverhead on Kirby Lane, according to the Riverhead Town Police Department.
Investigators said the truck was backing up when it collided with a parked dump truck. The impact left Javier Palma-Guevara, who was riding on the vehicle's back step, with serious injuries to his leg.
He was flown by police helicopter to University Hospital in Stony Brook for treatment. The extent of his injuries was not immediately clear.
Police said the garbage truck’s 50-year-old driver remained at the scene and is cooperating with investigators. He is not expected to face criminal charges.
Anyone with information is asked to contact the Riverhead Town Police Department at 631-727-4500.
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