KING TV NBC 5 - SEATTLE - Two teenage boys are in custody and facing charges for allegedly lighting off fireworks and setting fire to a Puyallup elementary school over the July Fourth weekend. The fire at Karshner Elementary School in Puyallup started around 11 a.m. Sunday, July 5. The flames quickly spread and firefighters on scene were forced to take a defensive approach and fight the fire from the outside of the building. It took hours for firefighters to put out the flames, and many crews had to stay on scene overnight to ensure the fire didn't start up again. The Puyallup Police Department and Fire Marshals immediately started investigating the cause of the fire and determined that two 15-year-old boys had been throwing fireworks into trash cans near one of the school buildings and it caught fire, according to a release from the police department Wednesday. The teens were arrested Wednesday and booked into Remann Hall for charges of arson in the first degree, police said. For additional information and video for this story, click here.