The youngster who fell from the roof of a two-story apartment was taken to a hospital but did not appear to have any broken bones, The Oregonian reported.
The boy landed in a flower bed, Vancouver Fire Department Capt. Scott Willis said.
While witnesses tended to the boy after the fall Sunday, awaiting medical help,13-year-old Damon Davenport, who was playing football in a nearby field, spotted an 18-month-old boy on the same roof.
Damon, who lives in the apartment building, ran up to the roof to save the child.
"I ran upstairs and opened the door, opened the window, kicked the screen," he said. "I grabbed the baby and handed it to [the tot's father]"
The children had apparently climbed out of a window and onto the roof, Willis said.