John Unu said volunteers from a group called the City Rescue Team found John Uaisele on the side of the Damon Slough on the western side of Interstate Highway 880 between the 66th Avenue and Hegenberger Road exits. "It's a sweet and sour day for my family," Unu said.
He said he's "very, very sad" that the boy was found dead but is "happy" that at least his body has been recovered.
Unu said the family will now go ahead and arrange funeral services for John Uaisele and his father, Petelo Uaisele.
The Oakland Fire Department searched for the boy Sunday and Monday but stopped its search Monday night.
Fire Department spokesman Lt. David Brue said this evening that he was on his way to the area where the boy was found.
He said Oakland police secured the scene and the Alameda County Coroner was heading to the site to recover the boy's body.
According to Oakland police, the boy was riding in a pickup truck with his family during a rainstorm around 7:30 p.m. Saturday when the truck crashed near Hamilton Street and Hegenberger Expressway, landing on its roof in a nearby flood control channel.
Petelo Uaisele, the driver of the vehicle, and four other people in the car, including the boy's mother and 1-year-old sister, were injured.
Oakland police said the accident appears to have occurred when a limousine bumped the rear of the pickup truck, causing Petelo Uaisele to lose control.
The vehicle rolled into a nearby canal and landed on its roof in 3-foot-deep water, Brue said.
Authorities said Petelo Uaisele was 19, but his wife, Mary Uaisele, said he was 25.
Brue said on Monday that authorities think fast-running water swept John Uaisele a long distance from the site of the accident.
Unu said members of the Mormon Temple in Oakland, which his family regularly attends, also helped in the search for John Uaisele and were at the scene when the boy's body was found.
He said, "We've been here every day from 7 a.m. to night."
Authorities said John Uaisele wasn't restrained at the time of the accident. But Mary Uaisele disputed that, saying he was buckled in but was swept away when someone tried to free him after the crash.