The Suffolk County Police Department said the crash happened at 10th Street Motocross in Ronkonkoma at about 12:45 p.m. on Sunday, Nov. 7.
Police said the 13-year-old Huntington boy rode his bike over a ramp when his rear tire struck the 18-year-old Massapequa Park man in the face.
The 13-year-old was airlifted to Stony Brook University Hospital to be treated for serious injuries, police said.
The 18-year-old was also taken to the same hospital for treatment of non-life-threatening injuries, SCPD reported.
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