The investigation continues today into the fire that burned St. Mary's Catholic Church in Amarillo.
The fire started early Monday morning, and now four days later investigators are still digging through the debris trying to figure out how it started.
Today federal agencies were also combing the scene alongside Amarillo fire investigators.
The Alcohol, Tobacco, and Firearms called in special dogs to search the site for traces of accelerants.
"Any time you have a building that has this type of damage then there is a significant amount of coverage, there's debris that covers areas where the fire may have occurred," says Amarillo Department Marshal Terry McKinney.
Which is making it difficult for officials, but several agencies are lending a helping hand.
"In any fire if the damage and size of the building exceeds the resources of the local fire marshal's office, that's what the ATF is for," says Captain Bob Johnson of Amarillo Fire Department.
Along with the Alcohol, Tobacco, and Firearms division, an accelerant detection canine from the Bedford Fire Department, near Fort Worth, is helping out.
"It cuts down our dig time as far as if they can go in and find something or not find something, it will help us narrow down an area we would be looking at," says Lt. Joey Lankford of the Bedford Fire Deparment.
Investigators say until a cause is determined, they will treat this as a crime scene.