WEST VALLEY CITY — Kent Costner was just coming from the store Wednesday with his wife when he noticed a glow coming from a vacant house that was being renovated.

"I saw three teens in the door. It looked like the front door was open. Then the glow started, then it got brighter and brighter," he said.

Realizing the house was on fire, Costner followed the three boys around the corner, got out of his car and told them to stop. Two of the boys ran off, but Costner was able to detain the third until police arrived.

The fire department arrived at the house, near 5600 West and 4100 South, about 8:30 p.m.

"Flames and smoke were bending out the windows," said West Valley Fire Capt. Kris Romijn.

It took crews about 40 minutes to put the fire out. The house, which has been under renovation for an extended period of time, was being transformed into the meeting hall for the Cambodian Christian Reformed Church.

The small house suffered an estimated $40,000 damage, most of it structural, Romijn said. Investigators do not believe the fire was the result of a hate crime, but rather mischievous kids.

"They said they did not know it was a church," Romijn said.

The boys, ranging in ages 13 to 15, said the door was open and their main intent was to paint graffiti. Setting a fire was an afterthought, Romijn said.

"They just decided to light a fire and it got out of hand," he said.

Costner, who is a bishop for the LDS ward in the area, said he knew one of the boys because his family members attend the ward. He said the problem with some of the boys is they don't have a father figure at home and go unsupervised too often.

"They're left to wander the street and get into mischief," he said. "They're not a part of anything. I feel sorry for them that they don't care about anything. They don't care about themselves or neighbors or anyone. I feel sad they don't want to care."

No charges had been filed as of Thursday afternoon. Investigators were trying to determine if the boys could be linked to any other recent fires in vacant houses.

E-mail: preavy@desnews.com