Downtown fire investigation continues

Tyler fire and A.T.F. agents tackled the investigation into Monday night's fire from pretty much all sides.

From up on top, and down below, investigators have been hard at work, literally getting to the bottom of things. They spent much of the day in the basement of the building, digging out debris and pumping out water. Investigators say saving the front of the building is also still a number one priority, but right now they're trying to nail down what caused the massive fire in the first place.

"We're just continuing to run different models as we work from the back of the building to the front, and as we work from the top down," said Scott Sweetow with the A.T.F. National Response team.

Investigators said North Spring Street will more than likely remain closed off through the weekend.