NAMPA -- A frantic search for a toddler who disappeared from his Nampa home came to a heartbreaking end Wednesday morning.

The body of 18-month-old Mason Cunningham was found at about 9 a.m. in Ten Mile Canal, about four miles downstream from his home, Canyon County Sheriff's officials say. The death remains under investigation, but Canyon County Sheriff's Office Capt. Bill Adams said investigators believe the boy wandered into the canal and was swept away by the swift-moving water.

Little Mason was last seen at about 8:30 p.m. Tuesday in the front yard of his home in the 6800 block of Ustick Road, near the 11th Avenue North extension.

The boy had been outside with a relative, officials say. The family member went around the house to turn on a sprinkler. By the time that person returned a few minutes later, Mason was gone.

"A search began by the parents of the local area around the house, and after determining he wasn't necessarily on the property, the father believed he may have been in the canal which is near the property," Adams said.

Although the home's backyard is fenced, there was no barrier between the canal and the front yard, investigators say.

The toddler's father jumped into the water to search for his son, and was swept downstream several blocks, before he was pulled out, Adams said. The Canyon County Sheriff's Office, other agencies and volunteers immediately began searching for the boy.

Officials brought tracking dogs from Meridian Police, combing the area without success until 2 a.m., officials say.

"Given the hour and the darkness, they discontinued the search," Adams said.

The hunt for Mason picked back up early Wednesday morning, with help from a police drone, a helicopter, multiple agencies and scores of volunteers. Mason's body was found Wednesday morning.

Adams said the crushed end to the search underscores the danger of canals, especially to young children.

"It's real easy to get into those canals, the canal banks are generally steep and overgrown, and especially somebody 18-months old, there's obviously no way they're going to get out of a canal," he said. "Just be aware of your surroundings and if you do live close to a canal, put up a fence or some sort of barrier to keep your children or pets away from the canal so that they don't end up in them."

Click below to watch the full news conference: