MESA, Ariz. -- A large debris fire is burning for a third day near the Loop 202 freeway in Mesa.
State highway patrol officers are monitoring the blaze Friday because of concerns that smoke could pose driver visibility issues along the freeway.
Authorities said it's still unclear what started the 15-foot pile of yard waste to start burning Wednesday. But they suspect it started spontaneously due to the natural breakdown of the organic material.
The fire poses challenges to fire crews due to the large amount of material fueling the flames.
Fire crews hope to break up the pile to speed up the burning process by using heavy equipment among other methods.
No structures have been threatened by the blaze.