A promising high-school football player was shot dead while riding his bicycle in Queens.

Shawn Plummer, 18, was riding with a friend on his handlebars a block from the Far Rockaway boardwalk when someone opened fire, a witness said.

“The guy on the handlebar was holding him, screaming, ‘You shot my brother! You shot my brother!’” the witness said. “It’s scary as hell . . . He shot him through the eye.”

The victim’s mother, Sharon Plummer, 46, said “he was headed to the corner store to buy something, and on the way back, that’s when it happened.”

“I heard the shots,” Sharon Plummer said.

“It was like about eight or nine rounds. When I heard it, I don’t know what came over me. I screamed out ‘Shawn!’ I felt a knot in my stomach and I cried out for him.”

Plummer was pronounced dead at St. John’s Hospital.