LOS ANGELES, California (CNN) -- A boy playing with matches started a Southern California wildfire that scorched more than 38,000 acres, the Los Angeles County Sheriff's Department said Tuesday.

A firefighter talks on a radio while battling the Buckweed blaze on October 22.

The Buckweed Fire, which destroyed 21 homes on its rampage, began October 21 in the Agua Dulce community.

"Our arson explosive detectives, in conjunction with the Los Angeles County Fire Department investigators, immediately began their investigation, and during the course of the investigation, it led to a juvenile suspect," Los Angeles County Sheriff's Deputy Tony Moore told CNN's "American Morning" Wednesday.

"After talking with that juvenile, he admitted to playing with matches, and accidentally starting the fire in that area," he said. Watch what's next for young suspect »

The boy, whose name and age were not given, is home with his parents, police said. The case will be presented to the Los Angeles County district attorney for possible charges.

According to the California Department of Forestry and Fire Protection, the Buckweed Fire burned 38,526 acres.

Sixty-three structures, 21 of them homes, were destroyed, and three civilians and two firefighters were injured.

The sheriff's department said the fire forced the evacuation of about 15,000 people.

As of Tuesday, 18 of 23 wildfires in Southern California were completely under control, and the remainder were at least 70 percent contained, according to the Department of Forestry and Fire Protection.

The fires are blamed for 14 deaths and charred more than 508,000 acres, destroying about 1,600 homes.

Five people were arrested in arson probes last week, and California Gov. Arnold Schwarzenegger on Saturday vowed to "hunt down" people responsible for setting wildfires.

Authorities said Saturday they were following 1,700 tips about a white Ford F-150 pickup seen near the origin of the sprawling Santiago Fire in Orange County.

Witnesses reported seeing the 1998-2004 model truck with chrome tubular running boards on Santiago Canyon Road on October 21 at about the time the Santiago Fire started.

Authorities said last week they had found evidence at the scene, although they declined to describe it.

"If I were one of the people who started the fires, I would not sleep soundly right now, because we're right behind you," Schwarzenegger said, urging the culprits to turn themselves in. E-mail to a friend

All About Wildfires • Arnold Schwarzenegger