The boy, who was not identified, was taken by ambulance to North Ottawa Community Hospital. He was treated and released on Tuesday.
A first-responder on the scene said the boy did not appear to have any major injuries. The boy was wearing a helmet, he said.
Pat Wessel said she had just left work and noticed the mo-ped coming down Third Street.
"He slowed way down at the corner," she said. "I slowed down, too, and I thought, 'Yeah, he's going to stop.'"
Wessel said she continued and felt a "boom."
Nancy Medacco of Grand Haven was parked nearby. She said she turned her head just in time to see the collision.
"I saw the bike explode," Medacco said. "He went off his bike, flipped around like a dead fish and came down."
Medacco said the boy tried to get up, but collapsed.
Her daughter, Chandra Amaya, a recent graduate of paramedic school, was one of the first people on the scene.