Carrollton police arrested a woman they say started a fire at a home that killed a two year old boy. The fire broke out around 3:30 a.m. at a home on Wild Plum Drive near Old Denton Road and Hebron Parkway, killing a two year old boy.   Investigators believe  Toni Barnett, the girlfriend of homeowner Christian Smalls, set Smalls’ bed on fire. Police say Smalls was able to rescue four of his children from an upstairs window by climbing upon the roof, but he couldn’t save the two year old. Barnett is being held at the Carrollton Police Department pending Capital Murder charges.